GASIFICATION OF BIO-OIL AND BIO-OIL/CHAR SLURRY by Masakazu Sakaguchi B.Sc., Kyoto University, 2003 M.Sc., Kyoto University, 2005 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in The Faculty of Graduate Studies (Chemical and Biological Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) April 2010 © Masakazu Sakaguchi, 2010 ii ABSTRACT Economic utilization of biomass as a fuel has been limited by transportation cost. One suggested remedy to address the problems of processing biomass on a large scale is to pyrolyze solid biomass at numerous local sites and transport the resulting liquid or liquid/char slurry to a large centralized conversion plant. This research involves the gasification of biomass fast pyrolysis oil, so called bio-oil, and a slurry mixture of bio-oil and fast pyrolysis char into synthesis gas. Kinetics of the reaction of steam with chars was studied using a thermo-gravimetric analyzer. Slurry Char was produced by pyrolysis of an 80 wt% bio-oil/20 wt% char mixture at nominal heating rates of 100–10,000°C/s. The resulting Slurry Char was subjected to steam gasification with 10–50 mol% steam at 800–1200°C. Reactivity of the Slurry Chars increased with the pyrolysis heating rate, but was lower than that of Original Chars. Kinetic parameters were established for a power-law rate model. Some measurements were initially done of gasification in CO2. A fluidized bed reactor, equipped with an atomization system, was constructed for gasification of bio-oil and slurry. The reactor contained either sand, or Ni-based catalyst. Experiments included gasification with pure steam and air. Effects of bed temperatures in the range 720–850°C, steam-to-carbon molar ratios of 2.0–7.5, and air ratios of 0–0.5 on gas composition and yields were tested. The carbon conversion of bio-oil to gas was found to be greater than that of slurry. The product gas composition was affected significantly by catalysis of the water-gas shift and the steam gasification. Greater yields of hydrogen and lesser yields of CO iii and hydrocarbons were found when catalyst was used. On a dry, inert-free basis, gases of up to 61% H2 were obtained. The data were compared with a thermodynamic equilibrium model. The product gas yield was reasonably predictable by the model. A mass and energy balance model of steam gasification in a dual-bed gasifier-combustor revealed that energy requirements are sensitive to the steam/carbon ratio and to the recovery of latent heat in the produced gas. iv TABLE OF CONTENTS ABSTRACT ................................................................................................................................. ii TABLE OF CONTENTS ............................................................................................................ iv LIST OF TABLES ..................................................................................................................... viii LIST OF FIGURES ...................................................................................................................... x NOMENCLATURE .................................................................................................................. xiv ACKNOWLEDGEMENTS ..................................................................................................... xvii CO-AUTHORSHIP STATEMENT ....................................................................................... xviii CHAPTER 1 Introduction ...................................................................................................... 1 1.1 Preface ................................................................................................................ 1 1.2 Fast pyrolysis of biomass ................................................................................... 3 1.3 Steam gasification of bio-oil .............................................................................. 8 1.3.1 Reactions in steam gasification .......................................................................... 8 1.3.2 Catalyst screening and developing ................................................................... 10 1.3.3 Steam gasification using fluidized bed reactors ............................................... 19 1.3.4 Feeding bio-oil and bio-oil/char slurry into a high-temperature gasifier ......... 19 1.3.5 Catalyst attrition in fluidized bed reactor ......................................................... 20 1.3.6 Synthesis gas production by gasification of bio-oil/char slurry ....................... 21 1.3.7 Equilibrium modeling ...................................................................................... 22 1.3.8 Research objectives .......................................................................................... 23 1.4 Thesis outline ................................................................................................... 24 1.5 References ........................................................................................................ 25 CHAPTER 2 Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio- Oil/Char Slurry .............................................................................................. 30 2.1 Introduction ...................................................................................................... 30 2.2 Experimental section ........................................................................................ 32 2.3 Treatment of experimental results .................................................................... 36 2.4 Results and discussion ...................................................................................... 37 2.4.1 The effect of pyrolysis heating rate .................................................................. 39 2.4.2 Effect of gasification temperature and steam pressure ..................................... 40 2.4.3 n-th order kinetics ............................................................................................. 43 2.5 Conclusion ........................................................................................................ 46 2.6 References ........................................................................................................ 47 v CHAPTER 3 Steam Gasification of Bio-Oil and Bio-Oil/Char Slurry in a Fluidized Bed Reactor ............................................................................................................ 49 3.1 Introduction ...................................................................................................... 49 3.2 Experimental equipment and methodology ...................................................... 50 3.2.1 Fluidized bed material ...................................................................................... 51 3.2.2 Gasification setup ............................................................................................. 54 3.2.3 Experimental procedure and calculations ........................................................ 57 3.3 Results and discussion ...................................................................................... 59 3.3.1 Effect of catalysis and temperature on bio-oil steam gasification ................... 61 3.3.2 Effect of space velocity and H2O/C ratio under non-catalytic steam gasification .......................................................................................................................... 64 3.3.3 Effect of feedstock and temperature on the product gas yield under catalytic steam gasification ............................................................................................. 66 3.3.4 Comparison with thermodynamic equilibrium ................................................ 69 3.3.5 Catalyst deactivation and attrition of bed material ........................................... 72 3.3.6 Surface changes after the bio-oil and the slurry gasification ........................... 73 3.4 Conclusions ...................................................................................................... 78 3.5 References ........................................................................................................ 80 CHAPTER 4 Partial Oxidation of Bio-Oil and Bio-Oil/Char Slurry in a Fluidized Bed Reactor ............................................................................................................ 82 4.1 Introduction ...................................................................................................... 82 4.2 Experimental details ......................................................................................... 83 4.2.1 Fluidized bed material ...................................................................................... 84 4.2.2 Gasification setup ............................................................................................. 85 4.2.3 Experimental procedure ................................................................................... 86 4.2.4 Definitions ........................................................................................................ 87 4.3 Results and discussion ...................................................................................... 88 4.3.1 Effect of air ratio .............................................................................................. 89 4.3.2 Effect of temperature ........................................................................................ 92 4.3.3 Difference between bio-oil and slurry in the product gas yield ....................... 95 4.3.4 Effect of catalysis ............................................................................................. 95 4.3.5 Comparison with thermodynamic equilibrium ................................................ 96 4.4 Conclusions .................................................................................................... 101 4.5 References ...................................................................................................... 102 CHAPTER 5 A Case Study of Steam Gasification in a Dual-Bed Gasifier .................... 103 5.1 Introduction .................................................................................................... 103 5.2 Model dual-bed gasifier system ..................................................................... 104 5.3 Equilibrium model for gasifier product gas composition ............................... 107 5.4 Results and discussion .................................................................................... 107 5.4.1 Effect of char content in slurry ....................................................................... 107 5.4.2 Etffect of H2O/C ............................................................................................. 110 vi 5.5 Conclusions .................................................................................................... 112 5.6 References ...................................................................................................... 113 CHAPTER 6 Conclusions and Suggestions for Further Work ....................................... 114 6.1 Conclusions .................................................................................................... 114 6.2 Recommended future work ............................................................................ 118 6.3 References ...................................................................................................... 120 APPENDICES APPENDIX A Research Note – CO2 Gasification Reactivity of Fast Pyrolysis Char ..... 122 A.1 Introduction .................................................................................................... 122 A.2 Experimental .................................................................................................. 122 A.3 Treatment of experimental results .................................................................. 123 A.4 Results and discussion .................................................................................... 124 A.5 Comparison with steam gasification reactivity .............................................. 125 A.6 Conclusion ...................................................................................................... 126 A.7 References ...................................................................................................... 128 APPENDIX B Material and Energy Balance Sheet, and Degrees of Freedom Analysis 129 B.1 Calculation sheets for mass and energy balance for Chapter 5 ...................... 129 B.2 Degrees of freedom in the dual-bed gasifier system ...................................... 138 B.3 Nomenclature ................................................................................................. 141 APPENDIX C Details of Apparatus ..................................................................................... 142 C.1 Recommendations for atomizer design .......................................................... 154 APPENDIX D Experimental Procedure .............................................................................. 156 APPENDIX E Flow Meter Calibrations .............................................................................. 160 APPENDIX F Location of Thermocouples and Pressure Transducers ........................... 171 APPENDIX G Experimental Data ....................................................................................... 172 APPENDIX H Sample Calculations ..................................................................................... 178 APPENDIX I Heat of Reactions of Steam Gasification, Steam Gasification Followed by the Water-Gas Shift Reaction, and Partial Oxidation of Bio-Oil ............ 185 I.1 Heat of reaction: steam gasification, steam gasification followed by the water- gas shift reaction and partial oxidation of bio-oil........................................... 185 I.2 Reference ........................................................................................................ 186 vii APPENDIX J Matlab Code for Thermodynamic Equilibrium Calculation ................... 187 J.1 Main program for free energy minimization (FEM) model RAND algorithm ........................................................................................................................ 187 J.2 Thermodynamic database ............................................................................... 204 J.3 Elemental abundance ...................................................................................... 215 J.4 Molar fraction of each species ....................................................................... 220 J.5 Standard chemical potential ........................................................................... 222 J.6 Species enthalpy ............................................................................................. 223 J.7 Elements in the RAND matrix ....................................................................... 224 J.8 Convergence forcer ........................................................................................ 227 J.9 Energy balance ............................................................................................... 228 J.10 Reference ........................................................................................................ 231 viii LIST OF TABLES Table 1.1 Bulk and energy densities of bio-oil, bio-oil/char slurry, wood pellets and wood chips (Sokhansanj, 2004; Bergman, 2005; Hamelinck et al., 2005) .................. 5 Table 1.2 Typical properties of wood derived crude bio-oil (source: Bridgwater et al., 2001) ................................................................................................................... 6 Table 1.3 Representative chemical composition of fast pyrolysis liquid (source: Bridgwater et al., 2001) ...................................................................................... 7 Table 1.4 Works on catalytic steam gasification of bio-oil, bio-oil aqueous fraction, model compounds of bio-oil and other biomass derived liquid ....................... 11 Table 2.1 Proximate analysis of Original Char in wt% .................................................... 35 Table 2.2 Ultimate analyses of bio-oil and Original Char in wt%; ash for char is shown in Table 2.1 ........................................................................................................... 35 Table 2.3 Total flow rate for gasification analysis ........................................................... 35 Table 2.4 Kinetic parameters determined and literature value for comparison ............... 44 Table 3.1 Proximate analysis of Original Char in wt% .................................................... 51 Table 3.2 Ultimate analyses of bio-oil and Original Char in wt%; bio-oil is shown in the wet basis and char is shown in the dry ash free basis ...................................... 51 Table 3.3 Metal analysis of the catalyst (RK-212) and the sand (*analyzed by whole rock fusion analysis, measured by ICP) ................................................................... 52 Table 3.4 Particle and fluidization properties of catalyst and sand in the steam gasification experiments (particle size: dp=180–355 m; gas viscosity: =3.7– 4.5×10 5 Pa·s; gas density: g=0.2 kg/m 3 ) ......................................................... 53 Table 3.5 Product gas composition (in mol%) and heating value from steam gasification of the bio-oil and the slurry with the catalyst and the sand at T≈800°C, H2O/C≈5.5, and GC1HSV≈340 h -1 ; wet with nitrogen and dry nitrogen free basis .................................................................................................................. 59 Table 3.6 Product gas composition (in mol%, dry N2 free basis) from steam gasification of bio-oil found in the literature ....................................................................... 60 Table 3.7. Metal analysis of the catalyst (RK-212) and the sand after gasification (*analyzed by icp after digestion by aqua regia) .............................................. 75 Table 4.1 Proximate analysis of Original Char in wt% .................................................... 84 Table 4.2 Ultimate analyses of bio-oil and Original Char in wt%; bio-oil is shown in the wet basis and char is shown in the dry ash free basis. ..................................... 84 ix Table 4.3 Product gas composition (in mol%) and heating value from partial oxidation of the bio-oil and the slurry with the catalyst and the sand at T≈842–848°C, H2O/C≈2.1, =0.5 and GC1HSV≈550–590 h -1 ; wet with nitrogen and dry nitrogen free basis ............................................................................................ 89 Table 5.1 Elemental analysis and water content of bio-oil and char in wt%, as-received. ........................................................................................................................ 106 Table A.1 Ultimate analysis and moisture content of char ............................................. 123 Table A.2 Activation energy for CO2 gasification: determined and literature value for comparison ..................................................................................................... 125 Table A.3 Gasification conditions for reactivity analysis in TGA (for comparison between steam and CO2) ............................................................................................... 125 Table B.1 Material and energy balance at H2O/C=5.5, char content=10 wt%, and carbon conversion of 83% .......................................................................................... 130 Table B.2 Material and energy balance at H2O/C=5.5, char content=15 wt%, and carbon conversion of 77% .......................................................................................... 131 Table B.3 Material and energy balance at H2O/C=5.5, char content=20 wt%, and carbon conversion of 70% .......................................................................................... 132 Table B.4 Material and energy balance at H2O/C=5.5, char content=25 wt%, and carbon conversion of 64% .......................................................................................... 133 Table B.5 Material and energy balance at H2O/C=5.5, char content=30 wt%, and carbon conversion of 56% .......................................................................................... 134 Table B.6 Material and energy balance at H2O/C=1.0, char content=20 wt%, and carbon conversion of 70% .......................................................................................... 135 Table B.7 Material and energy balance at H2O/C=3.0, char content=20 wt%, and carbon conversion of 70% .......................................................................................... 136 Table B.8 Material and energy balance at H2O/C=8.0, char content=20 wt%, and carbon conversion of 70% .......................................................................................... 137 Table F.1 Location of thermocouples and pressure transducers..................................... 171 Table G.1 Experimental data of partial oxidation #1 ...................................................... 173 Table G.2 Experimental data of partial oxidation #2 ...................................................... 174 Table G.3 Experimental data of partial oxidation #3 ...................................................... 175 Table G.4 Experimental data of steam gasification #1 ................................................... 176 Table G.5 Experimental data of steam gasification #2 ................................................... 177 Table H.1 Sample calculation for run ID: PO_OC14-2 .................................................. 178 x LIST OF FIGURES Figure 2.1 Typical Slurry Char weight loss curve during steam gasification experiment with TGA (Slurry Char B, 900°C, 10 kPa steam) (The final temperature was maintained for 5-15 minutes while distilled water was injected into the furnace through a syringe pump, generating steam inside the TGA furnace.) .............. 38 Figure 2.2 Typical Slurry Char steam gasification rate dX/dt during experiments (Slurry Char B, 900°C, 10 kPa steam) (The final temperature was maintained for 5-15 minutes while distilled water was injected into the furnace through a syringe pump, generating steam inside the TGA furnace.) ........................................... 38 Figure 2.3 Effect of pyrolysis heating rate on steam gasification reactivity of Slurry Char .......................................................................................................................... 40 Figure 2.4 Reactivity of chars at X=0.5; steam partial pressure at: (a) 10 kPa, (b) 30 kPa, and (c) 51 kPa ................................................................................................... 41 Figure 2.5 Original Char B steam gasification reactivity, steam effect (X=0.5); continuous lines show n-th order reaction model ............................................................... 42 Figure 2.6 Slurry Char B reactivity as a function of steam partial pressure and temperature (X=0.5); continuous lines show n-th order reaction model .............................. 42 Figure 2.7 Arrhenius plot of Original Char B steam gasification (X=0.5); dotted line indicates linear relationship for 800–1000°C ................................................... 45 Figure 2.8 Arrhenius plot of Slurry Char B steam gasification (X=0.5); dotted line indicates linear relationship for 800–1000°C ................................................... 45 Figure 3.1 Schematic of the steam gasification fluidized bed experimental apparatus ..... 56 Figure 3.2 Effect of catalysis on: a) carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4) ; and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) on the dry feed stock basis; under steam gasification, H2O/C≈5.5, GC1HSV ≈ 340 h -1 ........................................................................ 63 Figure 3.3 Steam conversion by steam gasification of the bio-oil and the slurry under catalytic and non-catalytic conditions .............................................................. 63 Figure 3.4 Effect of space velocity on: a) carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) on the dry feed stock basis; at T≈800°C and GC1HSV≈320 h -1 under non-catalytic steam gasification................................. 65 Figure 3.5 The effect of steam to carbon ratio on: a) carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2–C4); and b) hydrogen yield (mol% - atomic) xi as H2, CH4 and hydrocarbons (C2–C4) ; at H2O/C≈5.5 and T≈790°C under non- catalytic steam gasification .............................................................................. 65 Figure 3.6 Effect of temperature on: a) carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4), under catalytic steam gasification at H2O/C≈5.5, and GC1HSV≈340 h -1 ........................................................................................ 68 Figure 3.7 Comparison of feedstock under catalytic and non-catalytic steam gasification on: a) carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2- C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2- C4) at H2O/C≈5.6 and GC1HSV≈320 h -1 .......................................................... 68 Figure 3.8 a) Carbon yield as CO; and b) hydrogen yield as H2, compared with kinetically modified equilibrium model (725–836°C, H2O/C≈5.5, GC1HSV≈330 h -1 , ●: bio-oil – catalytic, ■: slurry – catalytic, ○: bio-oil – non-catalytic, □: slurry – non-catalytic, ♦: reference (Czernik et al., 2007) bio-oil – catalytic, ▲: reference (van Rossum et al., 2007) bio-oil – catalytic, ∆: reference (van Rossum et al., 2007) bio-oil – non-catalytic) ................................................... 71 Figure 3.9 Catalyst deactivation after 250 min of bio-oil partial oxidation (conparison of 1st run and 5th run on the same catalyst bed at =0.5 and ~845°C) ................ 73 Figure 3.10 a) SEM images of a) fresh catalyst; and b) fresh sand ..................................... 77 Figure 3.11 SEM images of catalyst surface after a) bio-oil gasification; and b) slurry gasification ....................................................................................................... 77 Figure 3.12 SEM images of sand surface after a) bio-oil gasification; and b) slurry gasification ....................................................................................................... 77 Figure 4.1 Schematic of fluidized bed partial oxidation experimental apparatus ............. 86 Figure 4.2 a) Carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) on the dry feed stock basis at catalytic partial oxidation, H2O/C=2.1, GC1HSV=510–600 h -1 ...................................................................................... 91 Figure 4.3 a) Carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) on the dry feed stock basis at non-catalytic partial oxidation, H2O/C=2.1, GC1HSV=510–600 h -1 ...................................................................................... 91 Figure 4.4 The effect of temperature on: a) the carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) the hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) ; with non-catalytic partial oxidation, H2O/C=2.1, GC1HSV=510–600 h -1 ; BO: bio-oil, SL: slurry ............................ 93 Figure 4.5 The effect of temperature on: a) the carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) the hydrogen yield (mol% - atomic) as xii H2, CH4 and hydrocarbons (C2-C4) with catalytic partial oxidation, H2O/C=2.1, GC1HSV=510–600 h -1 ; BO: bio-oil, SL: slurry ................................................ 94 Figure 4.6 a) Hydrogen yield as H2, and b) carbon yield as CO compared with modified equilibrium model ; 790–850°C, H2O/C=2.1, GC1HSV=510–600 h -1 , ●: bio-oil – catalytic, ■: slurry – catalytic, ○: bio-oil – non-catalytic, □: slurry – non- catalytic ............................................................................................................ 97 Figure 4.7 H2/CO ratio compared with modified equilibrium model; 790–850°C, H2O/C=2.1, GC1HSV=510–600 h -1 , ●: bio-oil – catalytic, ■: slurry – catalytic, ○: bio-oil – non-catalytic, □: slurry – non-catalytic ......................................... 98 Figure 4.8 a) Hydrogen yield as H2, and b) carbon yield as CO compared with modified equilibrium model; 790–850°C, H2O/C=2.1, GC1HSV=510–600 h -1 , ●: bio-oil – catalytic, ■: slurry – catalytic, ○: bio-oil – non-catalytic, □: slurry – non- catalytic .......................................................................................................... 100 Figure 4.9 H2/CO ratio compared with modified equilibrium model; 790–850°C, H2O/C=2.1, GC1HSV=510–600 h -1 , ●: bio-oil – catalytic, ■: slurry – catalytic, ○: bio-oil – non-catalytic, □: slurry – non-catalytic ....................................... 100 Figure 5.1 Schematic of dual-bed gasifier for bio-oil/char slurry steam gasification ..... 106 Figure 5.2 Effect of char contents in slurry on energy requirements and recycles (H2O/C=5.5) ................................................................................................... 109 Figure 5.3 Effect of char contents in slurry on bed material circulation rate and auxiliary fuel (slurry) amount (H2O/C=5.5) .................................................................. 109 Figure 5.4 Effect of H2O/C on energy requirements and recycles for 20% char in slurry ........................................................................................................................ 111 Figure 5.5 Effect of H2O/C on bed material circulation rate and auxiliary fuel amount for 20% char in slurry .......................................................................................... 111 Figure A.1 Effect of temperature on char reactivity in CO2 gasification ......................... 126 Figure A.2 Arrhenius type plot of char reactivity in CO2 gasification ............................. 127 Figure C.1 Locations of thermocouples and pressure transducers ................................... 142 Figure C.2 Detail of gasification reactor assembly .......................................................... 143 Figure C.3 Drawing of reactor top ................................................................................... 144 Figure C.4 Drawing of reactor bottom ............................................................................. 145 Figure C.5 Drawing of flange part ................................................................................... 146 Figure C.6 Drawing of distribution plate ......................................................................... 147 Figure C.7 Drawing of reactor lid for the bottom ............................................................ 148 Figure C.8 Drawing of reactor lid for the top ................................................................... 149 xiii Figure C.9 Drawing of graphite gasket ............................................................................ 150 Figure C.10 Drawing of internal cyclone ........................................................................... 151 Figure C.12 Drawing of cooling jacket .............................................................................. 152 Figure C.11 Drawing of atomizer slot ................................................................................ 152 Figure C.13 Drawing of spray nozzle adaptor ................................................................... 153 Figure C.14 Aircap and aircap body, assembled with spray nozzle adaptor with 1/8-inch- O.D. feedline .................................................................................................. 153 Figure C.15 Spray nozzle (former) assemble of Swagelok fittings with 1/16-inch-O.D. feed line .................................................................................................................. 153 Figure E.1 Calibration of the water pump at 50% stroke (IWAKI metering pump, adjustable stroke, model#: EWB15F1-PC) .................................................... 160 Figure E.2 Calibration of the pump for bio-oil or bio-oil/char slurry (CHEM-TECH peristaltic pump, model#: CTPD2HS1-PAP1-XXXXX) ............................... 161 Figure E.3 Calibration of Air/N2 flow controller for atomizer (air for partial oxidation; N2 for steam gasification) .................................................................................... 162 Figure E.4 Calibration of the flow controller for air introduced at the bottom of the reactor ........................................................................................................................ 163 Figure E.5 Calibration of N2 flow controller for atomizer in partial oxidation ............... 164 Figure E.6 Calibration of N2 flow controller for purging pressure transducer line at the bottom of the reactor ...................................................................................... 165 Figure E.7 Calibration of N2 flow controller for purging pressure transducer line at the top of the reactor ................................................................................................... 166 Figure E.8 Calibration of N2 flow controller for purging rupture disc line ..................... 167 Figure E.9 Calibration of N2 flow controller for H2/N2 mix from the reactor bottom for activating catalyst ........................................................................................... 168 Figure E.10 Calibration of H2 flow controller for H2/N2 mix from the reactor bottom for activating catalyst ........................................................................................... 169 Figure E.11 Calibration of N2 flow controller for purging outside the reactor inside the furnaces .......................................................................................................... 170 xiv NOMENCLATURE ADP 4-allyl-2,6-dimethoxyphenol Ar Archimedes number BO Bio-oil C2+ Hydrocarbons having more than one carbon atoms in its molecule C2–C4 Acetylene, ethylene, ethane, propylene, propane, iso-butane, 1-butene and butane D Diameter (m) dp Particle diameter (m) E Activation energy (J/mol) g Gravitational acceleration (m/s 2 ) GC1HSV Methane equivalent gas hourly space velocity (h -1 ) GHSV Gas hourly space velocity (h -1 ) HAA Hydroxyacetaldehyde HAc Acetic acid HHV Higher heating value (MJ/kg or GJ/m 3 ) H2O/C Steam to carbon molar ratio (mol/mol) I.D. Inner diameter (m) K Equilibrium constant k Rate constant (s -1 Pa -n ) k0 Frequency factor (s -1 Pa -n ) L Reactor length (m) xv LHSV Liquid hourly space velocity (h -1 ) n Reaction order regarding steam partial pressure. O.D. Outer diameter (m) P Pressure (Pa) PH2O Steam pressure (Pa) R Gas constant (J/(K·mol)) r(t) Reactivity at the time t (s -1 ) rmodel Reactivity calculated by model (s -1 ) SEM Scanning electron microscopy SL Bio-oil/char slurry t Time (s) T Temperature (K) TGA Thermogravimetric analyzer U Gas superficial velocity (m/s) Umf Minimum fluidization velocity (m/s) w(t) Weight of char at the time t (mg) w0 Weight of char at the beginning of the gasification (mg). wf Weight of char at the end of the gasification (mg). X(t) Fractional conversion H0298 Heat of reaction at 298 K (kJ/mol)  Air ratio (=1 achieves the complete combustion of feedstock)  Viscosity (Pa·s) xvi g Gas density (kg/m 3 ) p Particle density (kg/m 3 ) xvii ACKNOWLEDGEMENTS I am most grateful to my supervisors, Drs. Naoko Ellis and A. Paul Watkinson for their invaluable advice, support and encouragement without which this thesis would not have been achieved successfully. I would like to express my gratitude to Drs. John R. Grace and Peter V. Barr for kindly being members of my thesis committee and giving me critical and useful advice which have improved the quality of the thesis. My gratitude is also due Dr. Yong-Hua Li for advice on experimental work, and Mr. Gordon Cheng and Mr. Doug Yuen in the machine shop for their assistance with mechanical aspects of my experimental setup, as well as Mr. Alex Thng, Mr. Graham Liebelt, Mr. Charles Cheung and Mr. David Roberts for construction of the setup. Special thanks are given to Mr. Horace Lam and Mr. Richard Ryoo in the Stores for helping me with all kinds of procurement. My former and present officemates, research fellows, visiting students and undergraduate summer students have made my program an unforgettably great experience. I would also like to thank Dynamotive Energy Systems and VTT, Technical Research Centre of Finland Finland for providing bio-oil and fast pyrolysis char for the experimental study. Finally, I am deeply indebted to my wife Hiromi for understanding my enrolment in a program of long duration, and providing consistent encouragement. xviii CO-AUTHORSHIP STATEMENT I conducted all experimental work, data analysis, and prepared all the drafts of manuscripts (Chapters 2, 3 4 and 5) in this thesis. The drafts of manuscripts have been reviewed and strengthened through input given by my supervisors Dr. Naoko Ellis and Dr. A. Paul Watkinson. 1 CHAPTER 1 Introduction 1.1 Preface Biomass is a promising renewable resource which can contribute to the substitution of dwindling fossil resources over many parts of the world. The increased interest in renewable and sustainable resources is a result of concerns about climate change caused by anthropogenic greenhouse gas, mainly CO2 (IPCC, 2007), and demand for a secure supply of fuel, energy and chemicals. Biomass-derived fuels or chemicals obtained from short rotation forestry and other energy crops can contribute to reducing the net CO2 emissions. Increased biomass use for energy will be necessary to substitute for fossil fuels. Biomass is composed mainly of carbon, hydrogen and oxygen, and can be a source of chemicals and fuels. This need cannot be readily satisfied by other forms of sustainable energy: namely wind, solar, geothermal and hydro. In Canada, wood residues from the forest industry are an available unused biomass source of 43.1 Mt-carbon/year. This is equivalent to an energy value of about 1.54 EJ/year, or 19% of the national fossil fuel use (Wood and Layzell, 2003). In addition, there exists a large quantity of unharvested trees killed by infection of bule stain fungus distributed by pine beetles in the province of British Columbia, Canada. Approximately 580 million m 3 of trees (equivalent to 140 Mt carbon on the same basis (Wood and Layzell, 2003) ) have been killed since 1999 (Walton, 2009). Unharvested beetle killed trees increase the risk of wild fires due to their low water content; thus, the beetle killed trees need to be cut and used sooner than sound trees. Use Chapter 1. Introduction 2 of the beetle killed trees for biomass to gas conversion is one of several promising options for efficient consumption. Biomass can be converted to transportation fuels and chemicals by thermochemical processes. Production of synthesis gas from biomass is a key first step in the thermochemical route. Gasification of biomass may be carried out using either solid primary biomass or secondary products derived from pyrolysis processes. Steam gasification is a promising means to convert biomass since it produces synthesis gas, a mixture of hydrogen and carbon monoxide. The heat for this endothermic reaction can be provided by a separate combustion of char produced in the gasifier under conditions of incomplete carbon conversion. Therefore, there have been numerous studies on steam gasification of biomass using dual fluidized-bed gasifiers in which biomass is gasified by pure steam while residual carbon is combusted in a separated combustor (Shen et al., 2007; Pfeifer et al., 2009). In this way, steam gasification and combustion sections are completely separated, so that product gas from steam gasification can be obtained as non-diluted by N2 even when the combustion part uses air for combustion agent. The heat generated in the combustor is recycled in the form of hot particles which flow to the gasifier (Shen et al., 2007). Bio-oil, a product from the biomass fast pyrolysis process is a liquid with similar elemental composition to its original feedstock and with high bulk and energy density. When char, a byproduct of the fast pyrolysis process, is mixed with bio-oil, bio-oil/char slurry with even higher density is obtained (Table 1.1). This high bulk and energy density can reduce transportation costs to large scale centralized gasification plants; these costs have been a detrimental factor in large scale use of solid biomass resource. In addition, larger-scale Chapter 1. Introduction 3 centralized conversion plants can be operated due to expanding economical transportation area when bio-oil/char slurry is used (Henrich et al., 2009). Although there are reported studies on steam gasification and partial oxidation of bio-oil, studies on slurry gasification have been limited to high temperature partial oxidation (1200–1600°C). In the present work, gasification of bio-oil/char slurry is studied in comparison to that of bio-oil. Firstly, the kinetics of gasification reactivity of bio-oil/char slurry in steam gasification is studied. Secondly, the partial oxidation air gasification performance of bio-oil/char slurry is studied using a lab-scale fluidized bed gasification setup, and the results are compared to those of bio-oil. Thirdly, steam gasification of bio-oil/char slurry is also studied using the setup, and compared to that of bio-oil. The gas compositions are compared with values calculated by equilibrium and modified equilibrium models. 1.2 Fast pyrolysis of biomass Bio-oil is produced by fast pyrolysis of biomass. In the fast pyrolysis processes, biomass is heated to around 500°C within a few seconds in the absence of oxygen and decomposed to gas, vapour and char. The condensed liquid product from the vapour, bio-oil, is a dark brown coloured liquid of similar elemental composition to the feedstock biomass material (Bridgwater, 1999). The typical yield of the bio-oil from the fast pyrolysis processes is 75 wt% (Bridgwater, 1999), and reaches 90 wt% including char (Drift et al., 2006). The remaining product is wet gas, which can be used to provide the heat for the pyrolysis process. There are several reactor types for bio-oil production (e.g. fluid bed, transported bed, circulating fluid bed, rotating cone, ablative, vacuum), but the basic bio-oil producing procedures are quite similar (Bridgwater, Chapter 1. Introduction 4 1999). The energy efficiency of the fast pyrolysis process is up to 90% (Ostman et al., 2001, Drift et al., 2006). This is competitive with the other biomass densification processes (i.e., wood pellet production; 88% (Bergman, 2005)). Typical properties and components of bio-oil are shown in Tables 1.2 and 1.3 respectively (Bridgwater et al., 2001). A major factor of interest for a gasifier feedstock is its water content, which varies from 15 to 30 wt%, and affects the heating value. Due to organic acid compounds, bio-oil causes corrosion in fuel handling systems. In addition, bio-oil is thermally unstable, and also causes fouling in reactors due to oligomers and polymer precursors content which polymerize at high temperature (>80°C), and consequently, make bio-oil more viscous (Bridgwater, 1999). Therefore, upgrading or conversion to more stable fuels or chemicals is desirable for large scale usage in various purposes. Most of the char produced in wood pyrolysis has been separated from the crude bio-oil of Table 1.2. Chapter 1. Introduction 5 Table 1.1 Bulk and energy densities of bio-oil, bio-oil/char slurry, wood pellets and wood chips (Sokhansanj, 2004; Bergman, 2005; Hamelinck et al., 2005) Bulk density (kg m -3 ) Energy density (GJ-HHV m -3 ) Energy density (MJ-HHV kg -1 ) Bio-oil 1200 22.9 19.1 Bio-oil/char slurry (80/20 wt%) 1300 29.7 22.8 Wood pellets 650 12.4 19.1 Wood chips 220 2.3 10.5 Chapter 1. Introduction 6 Table 1.2 Typical properties of wood derived crude bio-oil (source: Bridgwater et al., 2001) Physical property Typical value Water content 15-30 wt% pH 2.5 Specific gravity 1.2 Elemental analysis (water free oil basis) C 55-58 wt% H 5.5-7.0 wt% O 35-40 wt% N 0-0.2 wt% Ash 0-0.2 wt% HHV as produced (depends on water content) 16-19 MJ/kg Viscosity (at 40C and 25% water) 10-40 cp Solids (char) 1 wt% Vacuum distillation residue Up to 50 wt% Chapter 1. Introduction 7 Table 1.3 Representative chemical composition of fast pyrolysis liquid (source: Bridgwater et al., 2001) Major Components wt% Water 20-30 Lignin fragments: insoluble pyrolytic lignin 15-30 Aldehyde: acetaldehyde, hydroxyacetaldehyde, glyoxal, methylglyoxal 10-20 Carboxylic acids: formic, acetic, propionec, butyric, pentanoic, hexanoic, glycolic, (hydroxy acetic) 10-15 Carbohydrates: cellobiosan, a- D- levoglucosan, oligosaccharides, anhydroglucofuranose 5-10 Phenols: phenol, cresols, guaiacols, syringols 2-5 Furfurals 1-4 Alcohols: methanol, ethanol 2-5 Ketones: acetol (1-hydroxy-2-propanone), cycle pentanone 1-5 Chapter 1. Introduction 8 The typical density of the bio-oil is 1200 kg/m 3 , and the density of the mixture of bio-oil and pyrolysis char (bio-oil/char slurry) is 1300 kg/m 3 (Drift et al., 2006). With typical higher heating values of ≈18 MJ/kg, the large energy densities of bio-oil and bio-oil/char slurry on a volumetric basis compared to biomass feedstock and their forms as liquid reduce the cost for long distance transportation and traffic density (Henrich et al., 2009). The bulk and energy densities of bio-oil and bio-oil/char slurry are compared in Table 1.1 with those of wood pellets and wood chips. Transportation costs of bio-oil and bio-oil/char slurry are lower than for wood chips and wood pellets because of the higher energy densities and relative ease of handling due to their liquid form, making them efficient media for transportation. 1.3 Steam gasification of bio-oil 1.3.1 Reactions in steam gasification Steam reforming of any oxygenated organic compounds proceeds according to the following overall reaction, CxHyOz + nH2O → n1CO2 + n2H2 + n3CO + n4CH4 + n6C2+ + n7C(s). (1.1) where CxHyOz is the empirical formula of oxygenated organic compounds, and x, y and z can be determined by ultimate analysis, and stoichiometric coefficients ni can be calculated by gas analysis for gases, and by material balance of carbon for solid carbon, when no tar is generated. If only CO and H2 are produced, the stoichiometric amounts are given in Equation (1.2), CxHyOz + (x - z)H2O → xCO + [(x + y/2 – z)]H2. (1.2) If the oxygenated organic compound is a solid or heavy liquid, Reaction (1.2) is usually termed steam gasification. This reaction is followed by the methanation (1.3) and shift equilibria (1.4): Chapter 1. Introduction 9 CO + 3H2  CH4 + H2O, H 0 298 = -205.8 kJ mol -1 (1.3) CO + H2O  CO2 + H2, H 0 298 = -41.2 kJ mol -1 (1.4) Depending on the conditions, the reverse Boudouard reaction may also occur, 2CO  CO2 + C, H0298 = -172 kJ mol -1 (1.5) Therefore, in the absence of solid carbon formation, the stoichiometric maximum yield of hydrogen that can be obtained is 2+(y-2z)/2x moles per mole of carbon in the feed material, as shown in following reaction, (Wang et al., 1996): CxHyOz + (2x-z)H2O → xCO2+(2x+y/2-z)H2 (1.6) According to Reaction (1.2), steam gasification of bio-oil proceeds according to, CH1.31O0.47 + 0.53H2O → CO + 1.185H2, H 0 298 = 108 kJ (mol carbon) -1 (1.7) where the elemental formula, CH1.31O0.47 is calculated from the elemental composition of a bio- oil produced from poplar wood at NREL (Diebold et al., 1999) which has the composition 57.3 wt% C, 6.3 wt% H, 36.2 wt% O, 0.2 wt% N on a water free basis, containing 18.9 wt% moisture on a wet basis. The nitrogen amount in the bio-oil is regarded as negligible. The heat of reaction is calculated using estimated heat of combustion of bio-oil -462 kJ (mol-carbon) -1 , -22.1 MJ (kg- water free bio-oil) -1 (Domalski et al., 1987). Details of the heat of reaction calculations are described in Appendix I. Because the steam gasification of bio-oil is an endothermic reaction, heat has to be provided for the reaction. If the shift reaction goes to completion, the maximum hydrogen yield corresponds to Reaction (1.8), CH1.31O0.47 + 1.53H2O → CO2 + 2.185H2, H 0 298 = 67 kJ (mol-carbon) -1 (1.8) which is also an endothermic reaction. Therefore, steam gasification requires heat for endothermic reactions. From Reaction (1.8), 171g of H2 can be obtained from 1 kg of the bio-oil Chapter 1. Introduction 10 at the maximum yield. However, the yield in practice is always lower than this value due to equilibrium reactions. 1.3.2 Catalyst screening and developing As summarized in Table 1.4, gasification of bio-oil and its components has been studied extensively. Owing to its complex components and unstable properties, many researchers have chosen simpler model compounds for experimental studies. Firstly oxygenated organic compounds of light molecular weight (e.g., acetic acid) were used for catalytic steam gasification study. Secondly, heavier oxygenated organic compounds (e.g., glucose, cellulose, phenol, etc.) were used to study steam gasification. Those tests with model compounds were followed by work on bio-oil aqueous fraction extracted by water, separating the oil phase of potential materials to be used as a source for valuable chemicals. Crude or straight bio-oil steam gasification followed those studies. Various catalyst screening or development studies on steam gasification for bio-oil have been conducted, with optimization of the catalyst mixtures. Ni, Pt, Ru, etc. on base materials of Al2O3, ZrO2, CeO2 or mixtures of them have been mainly studied by researchers (Table 1.4). From those studies, Ni/Al2O3 catalyst with promoters (e.g. Mg, Ca, K), which is a common composition in commercial naphtha steam reforming, is also found to be highly effective for bio-oil steam gasification in terms of H2 yield and conversion reducing carbon deposition on the catalyst, which deactivates catalysts. From their research on biomass steam or steam/O2 gasification in a fast fluidized-bed gasifier, it was also reported by Aznar et al. (1998) that commercial naphtha steam reforming catalysts generally remove tar, at high effectiveness. 1 1 C h a p ter 1 . In tro d u ctio n Table 1.4 Works on catalytic steam gasification of bio-oil, bio-oil aqueous fraction, model compounds of bio-oil and other biomass derived liquid Source Reaction Feed material Reactor type, size Catalyst Operating conditions Feed rate H2 Yield Wang et al., 1996, 1997 Steam gasification Model compounds: Acetic acid Methanol Cellulose Xylan Levoglucosan Lignin Aspen pyrolyzed vapour Phenol Syringol HAA in MeOH ADP in MeOH Packed bed micro reactor I.D. = 0.008 m Ni-based Commercial cat. UCI G-90C 15% Ni on Al2O3/CaAl2O4 Low temp. shift cat. UCI C18HC 42% CuO, 47% ZnO, 11% Al2O3(support)) (expect to reform low- molecular-weight alcohols and aldehydes) dp = 250-710 ×10 -6 m 0.0005 -0.001 kg When catalyst <0.25 g, mixed with quartz chips (250- 355×10-6 m ) ID = 0.008 m Bed height > 0.025 m, 300-730°C H2O/C = 4.5-7.5 GC1HSV = 336- 2240 h-1 Steam Acetic acid 86% Methanol 95% Cellulose 100% Xylan 100% Levoglucosan 100% Lignin 41% Aspen pyrolyzed vapour 62% at H2O/C=10-13 (Phenol 99%, Syringol 100%, HAA 96%) 20% in MeOH at H2O/C = 10-13 (ADP 69%) 41% in MeOH at H2O/C=4.5 Wang et al., 1998 Steam gasification Biooil aqueous fraction (poplar wood) Model compounds: Methanol, Acetic acid, Syringol, m-cresol Fixed bed reactor I.D. = 0.0165 m L = 0.426 m Commercial nickel-based catalysts UCI G-90C, UCI G-91, and dual-catalyst be of ICI 46-1 and 46-4 dp = 0.0024-0.004 m 0.1 kg 600-700°C H2O/C = 5-35 GC1HSV = 760- 2450 h-1 85% of stoichiometric potential from biooil aqueous fraction Catalysts can be easily regenerated by steam or CO2 gasification 1 2 C h a p ter 1 . In tro d u ctio n Source Reaction Feed material Reactor type, size Catalyst Operating conditions Feed rate H2 Yield Marquevich et al., 1999 Steam gasification Model compounds: Acetic acid, xylose, glucose, sucrose in water 20% m-cresol, dibenzyl ether 2 Fixed bed reactors 1. I.D. = 0.0264 m L = 0.41 m for acetic acid and xuccharides 2. I.D. = 0.0127 m L = 0.28 m for m-cresol, dibenzyl ether, acetic acid Rapid coking at T < 650°C with acetic acid Oxygenated aromatics can be completely converted to gases at T > 650°C, H2O/C = 3, GC1HSV > 8500 h -1 H2 yield = 70-90% of stoichiometric value Sugars are difficult to reform 1. dp = 0.0024-0.004 m, 0.1 kg, 50% Al2O3 diluted, 2. dp = 0.001-0.002 m, 0.01 kg 550-810°C, 500- 750°C for acetic acid 725, 800,875°C (m-cresol, benzyl ether) H2O/C = 3-6 1.5-2bar Reaction completed at 600°C 650°C H2O/C = 5 seems optimum GC1HSV: Acetic acid 784- 5466 h-1 M-cresol 8650 h-1 Benzyl ether 11790 h-1 Sugar 538-851 h-1 67-90% of stoichiometric potential Czernik et al., 1999, 2000, 2002, 2004 Steam gasification Biooil aqueous fraction (pine sawdust, poplar wood, pine wood, peanut shells) Steam aqueous fraction of poplar wood Methane Crude glycerin Trap grease Fluidized bed reactor D = 2 inch (nominal) C11-NK Sud-Chemie Entrained from reactor by 5%/day by attrition. Coke deposition at T = 800°C Low coke deposition at T = 850°C NREL prepared catalyst dp = 300-500 ×10 -6 m, 0.15- 0.25 kg 800,-850°C, 870-950°C (methane) H2O/C = Biooil aqueous fraction 7-9 Hemicellulose 9- 14 Methane 3.85- 7.1 Crude glycerin 2.1-2.6 Trap grease 2.7- 5.0 GC1HSV = 770- 1440 h-1 120-300 g/h 750°C Superheated steam 120-240g/h 90% of stoichiometric value from bio-oil aqueous fraction 1 3 C h a p ter 1 . In tro d u ctio n Source Reaction Feed material Reactor type, size Catalyst Operating conditions Feed rate H2 Yield Garcia et al., 2000 Steam gasification Biooil aqueous fraction (poplar wood) Packed bed micro reactor I.D. = 0.00785 m Many Ni-based catalyst (commercial and research) Lowest level of benzene Ni- Co/MgO-La2P3-Al2O3 and Ni- Cr/Mg)-La2O3-Al2O3 Mg and La enhance steam adsorption that facilitates the gasification of surface carbon Commercial catalysts for steam reforming of natural gas and crude oil fractions is more efficient for hydrogen production from bio-oil than most of the research catalysts mainly due to the higher water-gas shift activity dp = 355-600×10 -6 m 825-875°C H2O/C = 4.9- 11.0 GC1HSV = 62300- 126000 h-1 Steam (+ helium) 80-90% max. of stoichiometric potential Magrini-Bair et al., 2002 Steam gasification Bio-oil aqueous fraction (pine softwood) Fluidized bed reactor D = 2 inch (nominal) Ni, Mg, K were impregnated on 90% and 99% alumina particle dp < 45 mesh (354 ×10 -6 m) 850°C 150g/h steam 150g/h liquid < 95% of stoichiometric potential Kechagiopoulos et al., 2004 Steam gasification Model compounds of bio-oil and biogas: Ethylene glycol, Acetic acid, CH4-CO2 mixture at 6:4 with H2O at H2O/CH4=0.75-5 Fixed bed Sud-Chemie C11-9-09 EW dp = 180-500 ×10 -6 m 5wt% Ni on calcium aluminate for acetic acid 450-750°C H2O/C = 2.5-6 n.a. < 65-90% of stoichiometric potential Rioche et al., 2005 Steam gasification Bio-oil (beech wood) Model compounds: Acetic acid, Phenol, Acetone, Ethanol Fixed bed I.D. = 0.015 m L = 0.3 m Pt-CeZrO2, Rh-CeZrO2, Pd- CeZrO2, Pt-Al2O3, Rh-Al2O3, Pd-Al2O3 0.0001-0.0002 g 650-950°C H2O/C = 2-100 GC1HSV = 43-3090 h-1 0.2 drop/s < 100% of stoichiometric potential (GC1HSV = 43 h -1) Galdámez et al., 2005 Steam gasfication Model compound: acetic acid Fluidized-bed reactor was made of 316 stainless steel (SS316), and the distributor plate was composed of Inconel Ni/Al catalyst (160–320 ×10-6 m), 0.2 kg 650°C H2O/C=5.58 P=101 kPa GC1HSV=13 000– 62 000 h-1. 0.119 g H2/g acetic acid (eq. 0.122 g H2/g acetic acid) at GC1HSV=13000 h -1 1 4 C h a p ter 1 . In tro d u ctio n Source Reaction Feed material Reactor type, size Catalyst Operating conditions Feed rate H2 Yield Basagiannis and Verykios, 2006 Steam gasification Model compound: acetic acid microreactor consists of two 0.006 m O.D. sections of quartz tube, which serve as inlet and outlet to and from a quartz cell of 0.008 m o.d. Al2O3 and La2O3, and Ni catalyst supported on La2O3/Al2O3 carrier, 0.00001– 0.0001 kg(0.0005–0.005 m bed), particle size: 180–250 ×10-6 m; 550–800°C H2O/HAc molar ratio: 3, P = 101 kPa. Flow rate: _30 cm3/min; feed: 0.5% HAc, 1.5% H2O in He n.a. Kechagiopoulos et al., 2006 Steam gasification Bio-oil aqueous fraction Ethylene glycol Acetone Mixture of acetic acid, acetone and ethylene glycol Fixed bed reactor, internal surface covered by alumina, I.D.=0.01252 m, length=0.712 m, high-temperature stainless steel C11-NK Nickel based commercial naphtha reforming catalyst (Süd-Chemie, dp =180–500 ×10-6 m) mixed with SiC of dp =400 ×10-6 m average size Ethylene glycol: 600–700°C, H2O/C=2–6 Acetone: 600– 750°C, H2O/C=3–6 Ethylene glycol: 650–750°C, H2O/C=3–6 Bio-oil aqueous fraction: 600– 900°C, H2O/C=8.2 P=101 kPa Ethylene glycol: GC1HSV=1500 h -1 Acetone: GC1HSV=1500 h -1 Ethylene glycol: GC1HSV=1500 h -1 Bio-oil aqueous fraction: GC1HSV=300–600 h-1 Model compounds: <90% at T>600°C, H2O/C>3 Bio-oil aqueous fraction: ≈60% Takanabe et al., 2006 Steam gasification Model compound: acetic acid Fixed bed reactor Pt/ZrO2 catalyst, dp =300–600 ×10-6 m, 0.00005–0.0002 kg 875 K, H2O/C=5 GHSV=40000– 160000 h-1, 87% at initial stage, GC1HSV=40000 h -1 Basagiannis and Verykios, 2007 Steam gasification Model compound: acetic acid Bio-oil aqueous fraction (beech) Fixed bed Ru/MgO/Al2O3, dp <63 ×10 -6 m, loaded on 1) a monolith (1200 channels per inch2) 0.024 m in diameter, 0.04 m in length and weighing 0.0066 kg (loading 1.7 g/in.3) and 2) a monolith (2400 channels per inch2) 0.00185 kg of catalyst was loaded on a monolith 0.025 m in diameter, 0.024 m in length and weighing 0.0024 kg (loading 2.2 g/in.3) Acetic acid: 550–800°C Bio-oil aqueous fraction: 700– 800°C Acetic acid: 290- 470 cm3/min Bio-oil aqueous fraction: GHSV=4880– 16570 h-1 n.a. 1 5 C h a p ter 1 . In tro d u ctio n Source Reaction Feed material Reactor type, size Catalyst Operating conditions Feed rate H2 Yield Czernik et al., 2007 Steam gasification Bio-oil (hardwood) produced by Dynamotive Fluidized bed reactor I.D.=2inch (nominal) C11-NK Sud-Chemie (naphtha steam reforming) 4 laboratory formulated catalysts dp =300-500 ×10 -6 m 850°C H2O/C=5.8 GC1HSV=920 h -1 80–90% of stoichiometric potential Davidian et al., 2007 Gasification Bio-oil (beech wood residue) Double envelope stainless steel reactor Ni/Al2O3 catalyst (dp =200– 300 ×10-6 m) and K/La2O3- Al2O3 catalyst (dp =50–100 ×10-6 m) 700°C 1–15 mL/h 40% with K/La2O3–Al2O3 catalyst Ramos et al., 2007 Steam gasification Model compound: acetol Fluidized bed reactor (316 stainless steel), with Inconel distributor plate, inner section of 13.14 cm2, Mixture of sand (0.264 kg) and catalyst (Ni–Al, Ni–Al–La, and Ni–Co–Al) (0–0.003 g), (both are dp =160–320 ×10 -6 m) Non-catalytic: 450–650°C Catalytic: 600 and 650°C H2O/C=1.3–6 GC1HSV=5947– 22323 h-1 i.e. 0.166 g H2/g acetol with Ni–Al catalyst (eq. 0.171 g H2/g acetol), 650°C, H2O/C=4.6, GC1HSV=5947 h -1 Wang et al., 2007 Steam gasification Bio-oil Fixed bed micro reactor 12CaO·7Al2O3 catalyst, doped with Mg, K or Ce (0.0002 kg, dp =180–250 ×10 -6 m) 250–750°C H2O/C=1.5, 4.0 and 9.0 GC1HSV=10000 h -1 2–2.5 mole H2 yield/mole C fed at S/C=1.5–9.0, GC1HSV=10000 h -1 van Rossum et al., 2007 Steam gasification and partial oxidation Bio-oil (beech or pine wood chip) Fluidized bed reactor, SS310S, Diameter=0.108 m, Height=0.72 m (Freeboard, diameter=0.196 m, height=0.33 m) Nickel-Alumina catalysts: -Ni–K/La on alumina fluidizable catalyst (dp =200– 300 ×10-6 m) -KATALCO 23 (commercial methane reforming fixed bed catalyst) -KATALCO 46 (commercial naphtha reforming fixed bed catalyst) (dp =200–300 ×10 -6 m) -Sand (dp =150–450 ×10 -6 m) -Mixture of catalyst and sand 523–914°C H2O/C=1.0–3.2 =0–26% P<<100 kPa 0.2–2.5 kg/h-1 bio- oil to 4–9 kg bed material Steam gasification: 0–20% (stoichiometric) under non-catalytic 23–48% (stoichiometric) under catalytic Partial oxidation: 15% under non-catalytic at =23% 38–40% under catalytic at =23–26% 1 6 C h a p ter 1 . In tro d u ctio n Source Reaction Feed material Reactor type, size Catalyst Operating conditions Feed rate H2 Yield Bimbela et al., 2007, 2009 Steam gasification Model compound: 50wt% acetic acid aqueous solution, 19.73wt% acetol aqueous solution, and 6.54wt% n-butanol aqueous solution Micro reactor, fixed bed, I.D.=0.009 m, quartz tube, height=0.025 m Sand layer followed by coprecipitated Ni–Al catalyst layer (dp =200–320 ×10 -6 m) 550, 650, and 750°C Acetic acid 23% aqueous solution, H2O/C=5.58 for acetic acid and acetol, and 14.70 for n-butanol P: atmospheric GC1HSV=4789– 134400 h-1 (acetic acid) GC1HSV=34430– 172493 h-1 (acetol) GC1HSV=7759– 46222 h-1 (1- butanol) Acetic acid: GC1HSV<18000: achieved equilibrium composition GC1HSV>18000: decreased H2, CO and CO2 yields with increasing GC1HSV Acetol: GC1HSV=34430–56928 h -1: achieved equilibrium composition at initial stage GC1HSV>172493 h -1: decreased H2 yields with increasing GC1HSV 1-butanol: GC1HSV=7759 h -1: achieved equilibrium composition GC1HSV>11617 h -1: decreased H2 yields with increasing GC1HSV Domine et al., 2008 Steam gasification Bio-oil (beech) Fixed bed, double envelope stainless steel tubular reactor Cordierite monolith (0.002 kg, 0.02 m diameter, 0.017 m length) coated by either Pt/Ce0.5Zr0.5O2 or Rh/Ce0.5Zr0.5O2 700 and 780°C H2O/C=2.5, 5 and 10 P: n.a. 1–5 mL/h Best performance with Pt/Ce0.5Zr0.5O2: 70% at 780°C, H2O/C=10 with <1% methane Vagia and Lemonidou, 2008 Steam gasification, inert gasification Acetic acid and acetone Quartz tube reactor, O.D.=0.01 m, Ni, Rh or Ir on CaO·2Al2O3 and 12CaO·7Al2O3 dp =108–180 ×10 -6 m, 0.00005 kg with 0.0001 kg of quartz particles 550–750°C H2O/C=0 or 3, P=101 kPa Acetic acid: GC1HSV=34500 h -1 Acetone: GC1HSV=28500 h -1 Highest hydrogen yield is achieved with the 5 wt% Ni/CaO_2Al2O3 catalyst, while the 0.5 wt% Rh/CaO_2Al2O3 catalyst presents the highest resistant to coking Wu et al., 2008 Steam gasification Bio-oil (sawdust) Two-stage fixed bed reactor system, Two of I.D.=0.02 m, height=0.8 m stainless steel. 1st stage: dolomite, dp =0.002– 0.003 mm 2nd stage: YWC-95, Wuxi Quangya Co., Inc. Ni/MgO commercial catalyst, dp =0.002–0.003 mm 700–900°C H2O/C=1–16, P=101 kPa GHSV=1800– 14400 h-1 81.1% at 800°C, GC1HSV no more than 3600 h-1 1 7 C h a p ter 1 . In tro d u ctio n Source Reaction Feed material Reactor type, size Catalyst Operating conditions Feed rate H2 Yield Yaseneva et al., 2008 Steam gasification Ethanol quartz reactor (i.d. 0.0025 m) packed with a catalyst (0.00025– 0.0005 mm fraction) diluted with a quartz sand Al2O3 based catalyst doped with Ce-Zr and different components (Cu, Cu-Ni, Ru, Pt, La, Pr, Sm), dp =250–500 ×10-6 m, 0.00018 kg, diluted in a 1:10 weight ratio with quartz sand 650–800°C Volume composition EtOH:H2O:N2 = 1:4:5 fed into the reactor with the total flow rate 9 l/h The highest H2 yield was performed with Ru/Ce0.4Zr0.4Sm0.2/Al2O3 Marda et al., 2009 Partial oxidation Bio-oil/methanol mixture (50/50wt%) Microreactor, I.D.=11 mm (20 mm at entrance) Quartz wool 625–850°C O:C ratio 0.7– 1.6 n.a. Hu and Lu, 2009 (a, b) Steam gasification (a) Model compound: acetic acid, ethylene glycol, acetone, ethyl acetate, m-xylene and glucose (b) Model compound: methanol, ethanol, 1- propanol, butanol, 2- propanol, 1,2- propanediol, glycerol, propionaldehyde, acetone and propionic acid Fixed bed reactor, Ni/Al2O3 catalyst + quartz (50/50%) (a) 300–800°C H2O/C=6 P=101 kPa (b) 200–600°C H2O/C=6 P=101 kPa (a) LHSV=10.1 h-1 (b)LHSV=12.2 h-1 n.a. Güell et al., 2009 Steam gasification and partial oxidation Model compound: acetic acid Fixed bed reactor, I.D.=4 mm Pt/ZrO2 or Pt/CeO2 catalyst 100 mg (dp =300–600 ×10 -6 m) 700°C H2O/C=5 P=101 kPa GHSV=80000 h-1 Pt/ZrO2: 85% max. at initial (steam gasification) ~74% for 4h (1% O2 partial oxidation) Pt/CeO2: ~90% max at initial (steam gasification) 65–75% for 10 h (1% O2 partial oxidation) 1 8 C h a p ter 1 . In tro d u ctio n Source Reaction Feed material Reactor type, size Catalyst Operating conditions Feed rate H2 Yield Medrano et al., 2009 Steam gasification Model compound: acetol and acetic acid Fluidized bed reactor, I.D.=25.4mm, quartz tube Mixture of sand and Ni- alumina catalyst (dp =160–320 ×10-6 m), bed height=0.07 m, U/Umf=6 theoretically calculated 650°C H2O/C=5.58 P=101 kPa Acetol: GC1HSV=8200 h -1 –∞ (25000 h-1 for modified catalyst) U/Umf=6 Acetic acid: GC1HSV=6800 h -1 (25000 h-1 for modified catalyst) U/Umf=10 i.e.. Acetol: 0.0047 at GC1HSV=∞ 1 0.0822 at GC1HSV=51459 h -1 0.1342 at GC1HSV=25561 h -1 0.1624 at GC1HSV=14628 h -1 0.1664 at GC1HSV=8247 h -1 Ca/Al ratio 0.12, Mg/Al ratio 0.26, performed the best attrition durability for each mix. Ca/Al and Mg/Al ratio affected catalyst performance of acetic acid. Mg/Al mol ratio=0.26 showed best catalyst activity durability. Chapter 1. Introduction 19 1.3.3 Steam gasification using fluidized bed reactors The fixed bed reactor designed for conventional steam reforming of natural gas and naphtha is not suitable for thermally unstable complex liquids obtained from lignocellulosic biomass because of their tendency to decompose thermally and form carbon deposits in the upper layer of the catalyst and in the reactor freeboard (Czernik et al., 2002). However, using a fluidized-bed reactor, gasification of these complex liquids can be efficiently carried out with the aid of a commercial nickel catalyst. From the studies in Table 1.4, various biomass materials (pine sawdust-derived bio-oil aqueous fraction, steam aqueous fraction of poplar wood, methane, crude glycerine, and trap grease) have been steam-gasified in fluidized bed reactors with catalysts. H2 yields from various biomass-derived materials including straight bio-oil have approached or exceeded 80% of those theoretically possible for stoichiometric conversion at the gasification temperature around 800°C with Ni based catalyst. Bio-oil was also gasified with steam using the same equipment (Czernik et al., 2007). So far, their work has been limited to bio-oil aqueous fraction or straight bio-oil; bio-oil/char slurry has not been studied. Gasification properties of the slurry probably differ from those of bio-oil due to char content. The solid char may be expected to be less reactive than bio-oil. Therefore, a gasification study with slurry is worth conducting to develop gasification technology for this feedstock. 1.3.4 Feeding bio-oil and bio-oil/char slurry into a high-temperature gasifier Feeding bio-oil and bio-oil/char slurry into a high-temperature gasifier is a technical challenge because of its high viscosity and polymerization tendencies. Bio-oil is composed of numerous oxygenated compounds and rapidly polymerizes when heated to more than 80°C. Chapter 1. Introduction 20 Researchers who have conducted straight bio-oil gasification in fluidized bed reactors have used cooling devices for bio-oil feeding to prevent bio-oil from polymerizing and plugging in feeding lines (Czernik et al., 2007; Galdámez et al., 2005; van Rossum et al., 2007, 2009). In the present study, much effort has been made to design and install a working system for steady bio-oil and/or bio-oil/char slurry feeding and atomization. A cooling jacket was installed which fully surrounds the atomizing nozzle. In early work before the cooling jacket was added, plugging happened easily. Therefore, a cooling device is considered necessary for bio-oil and bio-oil/char slurry feeding unless devices which mechanically remove polymerized materials are installed. 1.3.5 Catalyst attrition in fluidized bed reactor Although numerous gasification studies have been conducted using commercial reforming catalysts, those catalysts were not specially designed for fluidized beds, but rather for fixed beds. Attrition of the catalyst in fluidized bed reactors is of importance. There appear to be no commercial attrition-resistant steam reforming catalysts available. Conventional catalysts are susceptible to attrition, and in prior work they were entrained from the reactor at a rate of 5%/day (Czernik et al., 2002). Attrition-resistant research catalysts were developed by Magrini- Bair et al. (2002); however, these are not commercially available. The support materials are 90 and 99% alumina particles made by Coorstek, Inc. with surface areas of 0.2 and 1.0 m 2 /g, respectively, an order of magnitude less surface area than Ni-based commercial catalyst (8.8 m 2 /g, Sud-Chemie C11-NK). Attrition losses of the catalysts were less than 0.5 wt%/day. Moreover, the smaller surface area did not significantly affect catalyst performance. Those attrition-resistant catalysts make the gasification system more feasible. Although attrition of Chapter 1. Introduction 21 catalyst is of importance when investigating process feasibility, conventional commercial catalysts are still effective for examining activity for short times. In addition, commercial catalysts are readily available and uniform in properties; the present study used a commercial catalyst for experiment. 1.3.6 Synthesis gas production by gasification of bio-oil/char slurry Gasification of bio-oil/char slurry with oxygen has been reported (Dinjus et al., 2004). The gasification was carried out in a 3–6 MW entrained flow gasifier at 26 bar. Slurry consisted of bio-oil and 23–26 wt% of char and 3 wt% of straw ash with char diameter of 10–1000 m. Slurry throughput was 0.35–0.5 t/h. Temperature was 1200–1600°C. The O2 gas feeding amount corresponded to =0.4–0.6 (where  isthe ratio of oxygen used to the stoichiometric amount for complete combustion). N2 was used for purging in the system. Complete carbon conversion (>99%) was obtained at high gasification temperature (>1000°C). Also, tar-free synthesis gas was obtained at 1200°C. This gasification process was thermodynamically controlled by available O2 and the approximate raw synthesis gas composition could be estimated from the water-gas shift equilibrium, {[CO2]·[H2]}/{[CO]·[H2O]} = K(T). (1.9) An example product gas composition was 47% CO, 21% H2, 18% CO2, and 15% N2 at 1200°C, =0.48, with char size of 94 m (<90%). Tar was not obtained at this condition. In this study, synthesis gas was obtained from bio-oil/char slurry by autothermal (partial oxidation) gasification in which pure oxygen was fed as gasifying agent, and provides heat for the Chapter 1. Introduction 22 endothermic gasification reactions. For example, the partial oxidation gasification of bio-oil proceeds according to, CH1.31O0.47 + 0.265O2 → CO + 0.655H2, (1.10) H0298 = -20 kJ mol -1 (per atomic mol carbon), or -0.97 MJ kg -1 (H2O free bio-oil). Exothermic Reaction (1.10) can be controlled by the oxygen feed rate. This process needs a facility for pure oxygen production that requires extra energy for the gasification, and a large scale process for sufficient efficiency. The present study of steam gasification of bio- oil/char slurry using a fluidized bed reactor with catalyst has not been reported. This approach produces a nitrogen-free synthesis gas from bio-oil/char slurry without air separation, by using steam as the gasifying agent. On the bench scale, electrical heaters provide the heat for this endothermic process. To investigate the feasibility, and for comparison of the process efficiency with that of steam gasification, catalytic gasification by partial oxidation of bio-oil/char slurry with/without steam is also investigated in the present study. 1.3.7 Equilibrium modeling Li (2002) investigated equilibrium modeling on biomass gasification in a circulating fluidized bed to predict the maximum achievable yield of desired products from a reaction system after infinitely long time for given operating conditions. This analysis is useful to understand the process, and provides a useful design aid for evaluating the possible limiting behaviour of the complex reacting system. Kinetic modifications were introduced to apply the model to such systems as a fluid bed gasifier operating at about 850°C which did not fully Chapter 1. Introduction 23 achieve equilibrium due to kinetic limitations. The present study uses a similar approach to predict product gas composition, and to obtain understanding of the process. 1.3.8 Research objectives The objectives of the present study are to investigate the following: (1) Steam gasification reactivity of char made from bio-oil/char slurry To estimate the properties in gasifiers, the reactivity of bio-oil/char slurry is needed. Assuming char in the slurry limits the overall gasification rate in a gasifier, the steam gasification reactivity of char made from the slurry is subject to investigation. After determining the effects of temperature and steam partial pressure on conversion over time, a kinetic model is proposed. (2) Steam gasification of bio-oil and bio-oil/char slurry in a fluidized bed reactor (2.1) Effect of operating conditions on product gas compositions and yields The effect of gasification temperature, steam to carbon feeding ratio, oxygen to carbon feeding ratio (for partial oxidation), space velocity of feed, and catalysis on product gas composition and yield are to be analyzed. The effect of char contained in the slurry on product gas is also studied. (2.2) Steam versus partial oxidation gasification In steam gasification, heat for the gasification is supplied solely by superheated steam and heat from external electrical furnace through the reactor wall. Since oxidation reactions provide heat for the endothermic reactions, steam gasification with partial Chapter 1. Introduction 24 oxidation is of interest for easy operation without large amount of heat transfer through the reactor wall. The effect of oxygen feed rate on the product gases is studied. (3) Comparison with an equilibrium model Experimental results are compared with values calculated by equilibrium models (e.g. Li, (2004)) at which the conversion to gas is the achievable maximum. A kinetically modified model is also compared with the results to test if the product gas composition and yield can be predicted by the model even when kinetic effects are not negligible. 1.4 Thesis outline The thesis is presented in a manuscript-based format. The thesis consists of the introduction chapter (Chapter 1), followed by research papers (manuscript-chapters) and a concluding chapter. In the manuscript-chapters, three studies on bio-oil and bio-oil/char slurry are shown. Chapter 2 shows the study on reactivity change between a fast pyrolysis char and the char made from rapid pyrolysis of a bio-oil/char slurry. By the analysis of rapid pyrolyzed Slurry Char, the reactivity of the slurry injection into the high temperature reactor system is investigated. Chapters 3 and 4 describe gasification studies using a lab-scale fluidized bed reactor with a bio-oil and a bio-oil/char slurry: Chapter 3 focuses on pure steam gasification of the bio-oil and the slurry; and Chapter 4 focuses on partial oxidation of the bio-oil and the slurry. Chapter 5 shows a case study of steam gasification in a dual-bed gasifier system, showing mass and energy balance. In Chapter 6, the comprehensive conclusions are given and recommendations for further works are presented. Chapter 1. Introduction 25 1.5 References Aznar, M. P., Caballero, M. A., Gil, J., Martin, J. A. and Corella, J. (1998) Commercial steam reforming catalysts to improve biomass gasification with steam/oxygen mixtures. 2. Catalytic tar removal. Industrial & Engineering Chemistry Research 37, 2668-2680. Basagiannis, A. C. and Verykios, X. E. (2006) Reforming reactions of acetic acid on nickel catalysts over a wide temperature range. Applied Catalysis A: General 308, 182-193. Basagiannis, A. C. and Verykios, X. E. (2007) Steam reforming of the aqueous fraction of bio- oil over structured Ru/MgO/Al2O3 catalysts. Catalysis Today, I.A. Vasalos Festschrift 127, 256-264. Bergman, P. C. A. (2005) Combined torrefaction and pelletisation: the TOP process. ECN-C-- 05-073, ECN (Energy research Center of Netherland) Biomass, Petten, Netherland. Bimbela, F., Oliva, M., Ruiz, J., García, L. and Arauzo, J. (2007) Hydrogen production by catalytic steam reforming of acetic acid, a model compound of biomass pyrolysis liquids. Journal of Analytical and Applied Pyrolysis, PYROLYSIS 2006: Papers presented at the 17th International Symposium on Analytical and Applied Pyrolysis, Budapest, Hungary, 22-26 May 2006 79, 112-120. Bimbela, F., Oliva, M., Ruiz, J., García, L. & Arauzo, J. (2009) Catalytic steam reforming of model compounds of biomass pyrolysis liquids in fixed bed: Acetol and n-butanol. Journal of Analytical and Applied Pyrolysis, Pyrolysis 2008 - Papers presented at the 18th International Symposium on Analytical and Applied Pyrolysis 85, 204-213. Bridgwater, A. V. (1999) An introduction to fast pyrolysis of biomass for fuels and chemicals, in Fast pyrolysis of biomass: a handbook, Bridgwater, S. V., Czernik, S., Diebold, J., Meier, D., Oasmaa, A., Peacocke, C., Piskorz, J. and Radlein, D. Eds., CPL Press, Newbury, Berkshire, pp. 1-13. Bridgwater, A. V., Czernik, S. and Piskorz, J. (2001) An overview of fast pyrolysis, in Progress in thermochemical biomass conversion, A. V. Bridgwater Ed., Blackwell Science, Oxford, vol.2, pp. 977-997. Czernik, S., French, R., Feik, C. and Chornet, E. (1999) Hydrogen from biomass via fast pyrolysis/catalytic steam reforming process. NREL/CP-570-26938, National Renewable Energy Laboratory, Golden, Colorado. Czernik, S., French, R., Feik, C. and Chornet, E. (2000) Production of hydrogen from biomass- derived liquids. NREL/CP-570-28890, National Renewable Energy Laboratory, Golden, Colorado. Chapter 1. Introduction 26 Czernik, S., French, R., Feik, C. and Chornet, E. (2002) Hydrogen by catalytic steam reforming of liquid byproducts from biomass thermoconversion processes. Industrial & Engineering Chemistry Research 41, 4209-4215. Czernik, S., French, R. J., Magrini-Bair, K. A. and Chornet, E. (2004) The production of hydrogen by steam reforming of trap grease-progress in catalyst performance. Energy & Fuels 18, 1738-1743. Czernik, S., Evans, R. and French, R. (2007) Hydrogen from biomass-production by steam reforming of biomass pyrolysis oil. Catalysis Today 129, 265-268. Davidian, T., Guilhaume, N., Iojoiu, E., Provendier, H. and Mirodatos, C. (2007) Hydrogen production from crude pyrolysis oil by a sequential catalytic process. Applied Catalysis B: Environmental 73, 116-127. Diebold, J. P., Milne, T. A., Czernik, S., Oasmaa, A., Bridgwater, A. V., Cuevas, A., Gust, S., Huffman, D. and Piskorz, J. (1999) Proposed specifications for various grades of pyrolysis oils, in Fast Pyrolysis of Biomass: handbook, Bridgwater, A. V., Czernik, S., Diebold, J. P., Meier, D., Oasmaa, A., Peacocke, C., Piskorz, J. and Radlein, D. Eds., CPL Press, Newbury, Berkshire, pp. 102-114. Dinjus, E., Henrich, E. and Weirich, F. (2004) A two stage process for synfuel from biomass, in IEA bioenergy agreement task 33: thermal gasification of biomass, task meeting, Vienna, May 3-5. Domalski, E. S., Jobe, T. L., Jr. and Milne, T. A. (1987) Thermodynamic data for biomass materials and waste components / sponsored by the ASME research committee on industrial and municipal wastes. American Society of Mechanical Engineers, New York. Domine, M. E., Iojoiu, E. E., Davidian, T., Guilhaume, N. and Mirodatos, C. (2008) Hydrogen production from biomass-derived oil over monolithic Pt- and Rh-based catalysts using steam reforming and sequential cracking processes. Catalysis Today, Selected Contributions of the XX Ibero-American Symposium of Catalysis 133-135, 565-573. Drift, A., Henrich, E. and Weirich, F. (2006) Synthesis gas from biomass for fuels and chemicals. ECN-C--06-001, Energy research Centre of Netherland, Pettenm Netherland. Galdámez, J. R., Garcia, L. and Bilbao, R. (2005) Hydrogen Production by Steam Reforming of Bio-Oil Using Coprecipitated Ni–Al Catalysts. Acetic Acid as a Model Compound. Energy & Fuels 19, 1133-1142. Garcia, L., French, R., Czernik, S. and Chornet, E. (2000) Catalytic steam reforming of bio-oils for the production of hydrogen: effects of catalyst composition Applied Catalysis, A: General 201, 225-239. Chapter 1. Introduction 27 Güell, B. M., Babich, I., Nichols, K. P., Gardeniers, J. G. E., Lefferts, K. and Seshan, K. (2009) Design of a stable steam reforming catalyst--A promising route to sustainable hydrogen from biomass oxygenates. Applied Catalysis B: Environmental 90, 38-44. Hamelinck, C. N., Suurs, R. A. A. and Faaij, A.P.C. (2005) International bioenergy transport costs and energy balance. Biomass and Bioenergy 29, 114-134. Henrich, E., Dahmen, N. and Dinjus, E. (2009) Cost estimate for biosynfuel production via biosyncrude gasification. Biofuels, Bioproducts and Biorefining 3, 28-41. Hu, X. and Lu, G. (2009, a) Investigation of the steam reforming of a series of model compounds derived from bio-oil for hydrogen production. Applied Catalysis B: Environmental 88, 376-385. Hu, X. and Lu, G. (2009, b) Investigation of the Effects of Molecular Structure on Oxygenated Hydrocarbon Steam Re-forming. Energy & Fuels 23, 926-933. IPCC (2007) Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment. Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K and Reisinger, A. (eds.)]. IPCC, Geneva, Switzerland, 104 pp. Kechagiopoulos, P., Vagia, E., Iordanidis, A., Voutetakis, S. S., Lemonidou, A. A. and Vasalos, I. A. (2004) Hydrogen production from renewable energy sources: reforming of biogas and bio-oil, in 2nd workshop CPERI, Thermi, Thessaloniki, 15-16, Dec. Kechagiopoulos, P. N., Voutetakis, S. S., Lemonidou, A. A. and Vasalos, I. A. (2006) Hydrogen Production via Steam Reforming of the Aqueous Phase of Bio-Oil in a Fixed Bed Reactor. Energy & Fuels 20, 2155-2163. Li, X., Grace, J. R., Lim, C. J., Watkinson, A. P., Chen, H. P. and Kim, J. R. (2004) Biomass gasification in a circulating fluidized bed. Biomass and Bioenergy 26, 171-193. Magrini-Bair, K., Czernik, S., French, R., Parent, Y., Ritland, M. and Chornet, E. (2002) Fluidizable catalysts for producing hydrogen by steam reforming biomass pyrolysis liquids. National Renewable Energy Laboratory, Golden, Colorado. Marda, J. R., DiBenedetto, J., McKibben, S., Evans, R. J., Czernik, S., French, R. J. and Dean, A. M. (2009) Non-catalytic partial oxidation of bio-oil to synthesis gas for distributed hydrogen production. International Journal of Hydrogen Energy 34, 8519-8534. Marquevich, M., Czernik, S., Chornet, E. and Montane, D. (1999) Hydrogen from biomass: steam reforming of model compounds of fast-pyrolysis oil. Energy & Fuels 13, 1160-1166. Chapter 1. Introduction 28 Medrano, J. A., Oliva, M., Ruiz, J., García, L. and Arauzo, J. (2009) Catalytic steam reforming of model compounds of biomass pyrolysis liquids in fluidized bed reactor with modified Ni/Al catalysts. Journal of Analytical and Applied Pyrolysis, Pyrolysis 2008 - Papers presented at the 18th International Symposium on Analytical and Applied Pyrolysis 85, 214-225. Ostman, A., Lindman, E. K., Solantausta, Y. and Beckman, D. (2001) A comparison of using wood pellets and fast pyrolysis liquid industrially for heat production within Stockholm, in Progress in Thermochemical Biomass Conversion, Bridgwater, A. V. Ed., Blackwell Science, Oxford, Vol.1, pp. 867-874. Pfeifer, C., Puchner, B. and Hofbauer, H. (2009) Comparison of dual fluidized bed steam gasification of biomass with and without selective transport of CO2. Chemical Engineering Science 64, 5073-5083. Ramos, M. C., Navascues, A. I., Garcia, L. and Bilbao, R. (2007) Hydrogen Production by Catalytic Steam Reforming of Acetol, a Model Compound of Bio-Oil. Industrial & Engineering Chemistry Research 46, 2399-2406. Rioche, C., Kulkarni, S., Meunier, F. C., Breen, J. P. and Burch, R. (2005) Steam reforming of model compounds and fast pyrolysis bio-oil on supported noble metal catalysts. Applied Catalysis B: Environmental 61, 130-139. van Rossum, G., Kersten, S. R. A. and van Swaaij, W. P. M. (2007) Catalytic and Noncatalytic Gasification of Pyrolysis Oil. Industrial & Engineering Chemistry Research 46, 3959-3967. Shen, L., Gao, Y. and Xiao, J. (2008) Simulation of hydrogen production from biomass gasification in interconnected fluidized beds. Biomass and Bioenergy 32, 120-127. Sokhansanj, S. and Turhollow, A. F. (2004) Biomass densification - Cubing operations and costs for corn stover. Applied Engineering in Agriculture 20, 495-499. Takanabe, K., Aika, K., Seshan, K. and Lefferts, L. (2004) Sustainable hydrogen from bio-oil- Steam reforming of acetic acid as a model oxygenate. Journal of Catalysis 227, 101-108. Takanabe, K., Aika, K., Seshan, K. and Lefferts, L. (2006) Catalyst deactivation during steam reforming of acetic acid over Pt/ZrO2. Chemical Engineering Journal, A special thematic issue on catalyst deactivation 120, 133-137. Vagia, E. C. and Lemonidou, A. A. (2008) Hydrogen production via steam reforming of bio-oil components over calcium aluminate supported nickel and noble metal catalysts. Applied Catalysis A: General 351, 111-121. Yaseneva, P., Pavlova, S., Sadykov, V., Alikina, G., Lykashevich, A., Rogov, V., Belochapkine, S. and Ross, J. (2008) Combinatorial approach to the preparation and characterization of Chapter 1. Introduction 29 catalysts for biomass steam reforming into syngas. Catalysis Today, Recent Developments in Combinatorial Catalysis Research and High-Throughput Technologies 137, 23-28. Walton, A. (2009) Provincial-level projection of the current mountain pine beetle outbreak: update of the infestation projection based on the 2008 provincial aerial overview of forest health and revisions to the “model” (BCMPB.v6). BC Ministry of Forest and Range, http://www.for.gov.bc.ca/hre/bcmpb/BCMPB.v5.BeetleProjection.Update.pdf. Retrieved Jan. 25, 2010. Wang, D., Montane, D. and Chornet, E. (1996) Catalytic steam reforming of biomass-derived oxygenates: acetic acid and hydroxyacetaldehyde. Applied Catalysis A: General 143, 245- 270. Wang, D., Czernik, S., Montane, D., Mann, M. and Chornet, E. (1997) Biomass to hydrogen via fast pyrolysis and catalytic steam reforming of the pyrolysis oil or its fractions. Industrial & Engineering Chemistry Research 36, 1507-1518. Wang, D., Czernik, S. and Chornet, E. (1998) Production of hydrogen from biomass by catalytic steam reforming of fast pyrolysis oils. Energy & Fuels 12, 19-24. Wang, Z., Pan, Y., Dong, T., Zhu, X., Kan, T., Yuan, L., Torimoto, Y., Sadakata, M. and Li, Q. (2007) Production of hydrogen from catalytic steam reforming of bio-oil using C12A7-O-- based catalysts. Applied Catalysis A: General 320, 24-34 (2007). Wood, S. M. and Layzell, D. B. (2003) A Canadian biomass inventory: feedstocks for a bio- based economy. BIOCAP Canada foundation. Wu, C., Huang, Q., Sui, M., Yan, Y. and Wang, F. (2008) Hydrogen production via catalytic steam reforming of fast pyrolysis bio-oil in a two-stage fixed bed reactor system. Fuel Processing Technology, Dimethyl Ether Special Section 89, 1306-1316. 30 CHAPTER 2 Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-Oil/Char Slurry 1 2.1 Introduction Biomass is considered a promising renewable resource which contributes to the world- wide needs for substitution of fossil resources. It is available in large amounts, and can be converted to transportation fuels and chemicals. Pyrolysis of biomass yields vapours, gas and char. In fast pyrolysis processes, biomass is heated to around 500°C within a few seconds in the absence of oxygen. The condensed product, bio-oil or pyrolysis oil, is a brown coloured liquid having similar elemental composition to the feedstock biomass (Bridgwater et al., 2001). As a high density liquid (typically 1200 kg/m 3 ), bio-oil can be readily stored, and pumped, leading to reduced transportation cost compared to dry biomass. When mixed with char, a product of the same process, bio-oil/char slurry of density 1300 kg/m 3 and energy density 30 GJ-HHV/m 3 can be prepared (80 wt% bio-oil/20 wt% char). Steam gasification of the slurry yields synthesis gas which is an attractive product, since high quality fuels and chemicals can be produced via Fischer-Tropsch synthesis. Therefore a study of steam gasification of bio-oil and its slurry has been undertaken. Bio-oil is composed of many oxygenated compounds derived originally from cellulose, hemi-cellulose and lignin. Thus, simple and light model compounds such as acetic acid, acetone, and other light oxygenated compounds which are components of bio-oil, were first studied in steam reforming (Wang et al., 1997; Wang et al., 1998; Czernik et al.,1999; Marquevich et al., 1 A version of this chapter has been submitted for publication. Sakaguchi, M., Watkinson, A. P. and Ellis, N. Steam gasification reactivity of char from rapid pyrolysis of bio-oil/char slurry. Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 31 1999; Garcia et al., 2000; Magrini-Bair et al., 2002; Rioche et al., 2005). After the light model compounds, heavier and more complex components such as phenols and hemicellulose, were gasified with steam (Czernik et al., 2002; Kechagiopoulos et al., 2006; Basagiannis and Verykios, 2007). With the idea of an integrated bio-oil use, the bio-oil aqueous fraction, rich in hemicellulose, was gasified, and the non-aqueous fraction, rich in pyrolitic lignin, was retained for production of valuable chemicals (Czernik et al., 2002). When heavy model compounds or lignin-derived compounds were gasified with catalyst, carbon tended to deposit on the catalyst surface, resulting in deactivation. Probably because of the difficulty in gasifying heavy compounds, whole bio-oil steam gasification research started only recently (Czernik et al., 2002; van Rossum et al., 2007; Wu et al., 2008; Davidian et al., 2007; Iojoju et al., 2007; Domine et al., 2008). On the other hand, steam gasification reactivity of wood char, similar to Original Char in a bio-oil/char slurry, was investigated earlier (Barrio et al., 2001), giving kinetic parameters for n-th order and Langmuir-Hinshelwood kinetic models. Similarly, sawdust was gasified with steam in a fluidized bed continuous gasifier, giving kinetic parameters for the n-th order kinetic model (Kojima et al., 1993). In this process, it can be assumed that the sawdust was pyrolyzed instantly after injection, and the resulting char was gasified by steam at a slow rate. The kinetic parameters are comparable to values from steam gasification of wood char. Despite much work on steam gasification of bio-oil and wood char, research for bio-oil/char slurry is limited to studies of oxygen blown pressurized entrained flow gasification at 1200-1600°C, to produce synthesis gas (Dinjus et al., 2004; Henrich, 2005). In addition, up to now, steam gasification kinetics have been studied for bio-oil and wood char only separately. The kinetic study of steam Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 32 gasification of bio-oil/char slurry has not been reported, even though the kinetics of steam gasification of the slurry are important for a gasifier design. We report on the gasification reactivity of bio-oil/char slurry, applicable to a steam- blown fluidized bed gasifier operating at temperatures of 800–1200°C. In the present study, it was assumed that the slurry is injected into a high-temperature gasifier, and rapidly pyrolyzed: the bio-oil components are first evaporated and/or decomposed rapidly, and then the resultant char is gasified with steam. Since the pyrolyzed bio-oil components might result in carbon deposition on the surface of the resultant char, steam gasification reactivity of the resultant char might be different from Original Char by the rapid pyrolysis upon injection. Therefore, steam gasification reactivity of char made by rapid pyrolysis of bio-oil/char slurry (Slurry Char) was analyzed, simulating injection of the slurry into a gasifier. The effect of heating rate during char preparation, and the steam concentration on the gasification rate were further analyzed. Kinetic parameters were determined according to the n-th order kinetic model, and compared with values from the literature. 2.2 Experimental section Two bio-oils were used in the present study. Bio-oil A produced from birch and aspen forest thinning in Finland was provided by VTT, Technical Research Centre of Finland. Bio-oil B, produced from wood in a commercial scale fast pyrolysis plant, was provided by Dynamotive Energy Systems corporation in Canada. Original Chars A and B were the by-products of bio-oil production through fast pyrolysis (~500°C, a few seconds), separated from hot pyrolyzed gas by a cyclone, provided by Dynamotive Energy Systems corporation. Bio-oil B and Original Char B Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 33 were produced from the same feed stock at the same plant at yields of 60–75 wt%, and 15–20 wt%, respectively. Proximate analysis of the Original Chars and the ultimate analysis of Original Chars and the bio-oils are shown in Tables 2.1 and 2.2. Two bio-oil/char slurries were prepared by mixing 80 wt% bio-oil and 20 wt% Original Char: 1) a mixture of 80 wt% bio-oil A and 20 wt% Original Char A (slurry A); and 2) a mixture of 80 wt% bio-oil B and 20 wt% Original Char B (slurry B). Prior to mixing, char samples were crushed and sieved to a particle size below 38 m. Particle sizes of the Original Chars were measured using a Mastersizer 2000 (Malvern Instruments): Original Char A was 18.7 m and Original Char B was 14.6 m (median). Prepared slurry samples were pyrolyzed using a Pyroprobe 1000 (CDS Analytical Inc.) in which heating rate can be set at nominal values of 10–100,000°C/s. The slurry (ca. 20 mg) was placed in a quartz tube (O.D. = 2.5 mm, I.D. = 1.9 mm and Length = 25 mm). The tube was inserted in a coiled electric heating element made of platinum, which was then placed in a small chamber (ca. 20 ml) with nitrogen purge at a flow rate of 100 ml/min. After purging the chamber with nitrogen for 5 minutes, the slurry was pyrolyzed by the heating element. The heating rate and temperature are electronically controlled by the Pyroprobe 1000. The quartz tube was heated to 800–1200°C at heating rate settings of 100, 1000 and 10,000°C/s on the equipment, and the final temperature was held for 30–60 seconds. It was not possible to check if the actual heating rates were equal to the nominal heating rates given by settings of the instrument. After pyrolysis, the resulting char (Slurry Char) was collected from the quartz tube and ground to a particle size below 38 m. Slurry Char was gasified with steam in a thermogravimetric analyzer (TGA) (TA instruments Q600), which consists of a horizontal balance beam which holds a sample pan with Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 34 thermocouple in contact with the pan. Either Original Char or Slurry Char (ca. 2 mg) was placed on an alumina pan, dried at 110°C for 5 minutes in nitrogen, and then heated to gasification temperature at the heating rate of 50°C/min. The final temperature was maintained for 5-15 minutes while distilled water was injected into the furnace through a syringe pump, generating steam inside the TGA furnace. For smooth steam generation, a diffuser was placed in the furnace at the water tubing outlet. Steam was mixed with nitrogen in the furnace and reacted with the Slurry Char. The steam pressure was calculated assuming ideal gas. From the precission of the water pump and the mass flow controller in TGA, the accuracy of steam pressure was calculated to be ±3.2%. To reduce diffusion effects between the sample and bulk gas phase, a shallow sample pan (0.5 mm depth) was used. The total gas flow rate for each gasification temperature was set as shown in Table 2.3. From preliminary experiments with varying total gas flow rate, it was found that the gasification took place with very little effect of diffusion between 800– 1000°C. Above 1000°C, a diffusion resistance appeared to significantly affect the gasification kinetics. BET surface area of partially gasified Slurry Char was measured with N2 at 77 K via a multi-point method used with a Micrometritics ASAP2020 surface area analyzer. The data from Original Char and Slurry Char were compared. Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 35 Table 2.1 Proximate analysis of Original Char in wt% Sample Moisture Volatile Matter (dry basis) Fixed Carbon (dry basis) Ash (dry basis) Char A 2.8 24.2 75.8 2.4 Char B 2.3 27.1 67.1 5.8 Table 2.2 Ultimate analyses of bio-oil and Original Char in wt%; ash for char is shown in Table 2.1 Sample C H N O (by diff.) *Bio-oil A 41.2 6.9 <0.3 51.9 *Bio-oil B 44.3 6.9 <0.3 48.8 Char A 80.1 3.6 0.05 13.8 Char B 73.7 3.5 0.12 16.9 *Ultimate analysis of bio-oils was done by Canadian Microanalytical Service Ltd., Delta, British Columbia Table 2.3 Total flow rate for gasification analysis Gasification temperature, °C Flow rate, ml/min* 800 200 900 300 1000–1200 400 *Flow rate was set as large as possible in order to reduce diffusion effect around the char sample. Flow rates at 800–900°C were lower due to steam generation restriction in the TGA furnace. Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 36 2.3 Treatment of experimental results In the present study, the char reactivity at a given time was defined as:   dt wtwd wtw tr f f    )( )( 1 )( (2.1) The degree of conversion, X(t) was obtained by: f f ww wtw tX    0 )( 1)( (2.2) Combining Equations 2.1 and 2.2 gave reactivity as a function of degree of conversion: dt dX X Xr   1 1 )( (2.3) In this study, steam gasification reactivity of chars was evaluated using Equation 2.3. Kinetic parameters for steam gasification reactivity of the Original Char and Slurry Char at X=0.5 were obtained for n-th order kinetic model instead of Langmuir-Hinshelwood kinetic model, assuming the kinetics is simply controlled only by steam pressure and temperature at the targeted temperature range. n OH kPr 2  (2.4) where        T E kk R exp 0 (2.5) as is commonly used for general char gasification kinetics (Barrio et al., 2001; Kojima et al., 1993). Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 37 Char steam gasification was carried out three times for each experimental condition, and a mean of each condition is shown on results figures with error bars indicating standard deviations. Kinetic parameters were determined by multiple regression of linearized form of Equations 2.4 and 2.5, OH0 2 ln R lnln Pn T E kr  (2.6) Estimated kinetic parameters are shown with 95% confidence intervals. Those kinetic parameters were also determined by non-linear fitting in which the sum (rmodel-r) 2 /r 2 ) was used to minimize non-uniform errors. The weight function 1/r 2 equalizes all data points distributed in 2 orders of magnitude. 2.4 Results and discussion Figures 2.1 and 2.2 show a typical weight loss curve and gasification rate X(t) change during a gasification experiment in the TGA. The first weight loss is release of volatiles in the char, followed by the second weight loss by steam gasification. The initial weight (w0) and the final weight (wf) for the steam gasification are indicated in the figures. Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 38 Figure 2.1 Typical Slurry Char weight loss curve during steam gasification experiment with TGA (Slurry Char B, 900°C, 10 kPa steam) (The final temperature was maintained for 5-15 minutes while distilled water was injected into the furnace through a syringe pump, generating steam inside the TGA furnace.) Figure 2.2 Typical Slurry Char steam gasification rate dX/dt during experiments (Slurry Char B, 900°C, 10 kPa steam) (The final temperature was maintained for 5-15 minutes while distilled water was injected into the furnace through a syringe pump, generating steam inside the TGA furnace.) 0.0 0.5 1.0 1.5 2.0 2.5 0 20 40 60 80 100 Time, min W ei g h t, m g 0 200 400 600 800 1000 T em p er at u re , °C 0.000 0.001 0.002 0.003 0 20 40 60 80 100 Time, min d X /d t, s -1 0 200 400 600 800 1000 T em p er at u re , °C Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 39 2.4.1 The effect of pyrolysis heating rate Figure 2.3 shows the reactivity of Slurry Char A prepared by rapid pyrolysis at 900°C and heating rates of 100°C/s, 1000°C/s and 10,000°C/s as a function of conversion. The reactivity increased with the degree of conversion in a similar manner for all samples. The reactivity of Slurry Char A was close to that of Original Char A at X=0.2 and X=0.4, while it was 11~27% lower than the value for Original Char A at X=0.6 and 21~38% lower at X=0.8. For the Slurry Char, a higher pyrolysis heating rate resulted in higher gasification reactivity, and the reactivity difference between Original Char and Slurry Char became larger in the final stages of the reaction. This can be explained by differences in surface area. At X=0.5, BET surface area was 920 m 2 /g in Original Char A, and 790 m 2 /g for Slurry Char A formed by rapid pyrolysis at the heating rate of 100°C/s. This difference in surface area is consistent with the difference in reactivity from Original Char A to Slurry Char A. Considering that the gasification rate at 900°C is largely controlled by reaction rate at the char surface rather than diffusion resistance (as is explained below), then the surface area will affect the reactivity at this temperature. Therefore, rapid pyrolysis of bio-oil/char slurry made the resulting char less reactive in steam than Original Char produced with the bio-oil. As well, the lower the heating rate, the less reactive is the resultant char. For efficient steam gasification of bio-oil/char slurry, the system should be chosen such that the heating rate of slurry is as high as possible in order that the resulting char be most reactive. Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 40 Figure 2.3 Effect of pyrolysis heating rate on steam gasification reactivity of Slurry Char 2.4.2 Effect of gasification temperature and steam pressure Figure 2.4 shows the results of steam gasification reactivity of Original Char B and Slurry Char B at X=0.5 as a function of temperature at different steam partial pressures: 10, 30 and 51 kPa. Steam gasification reactivity of Slurry Char B was close to that of Original Char B. At PH2O=10 kPa, maximum reactivity was ~0.04 s -1 whereas at higher steam pressure of 30 and 51 kPa, the maximum reactivity reached higher than 0.1 s -1 . At a fixed steam partial pressure of 30 kPa, the reactivity increased from 0.0004 s -1 to 0.1 s -1 , a factor of 250, as the temperature was raised from 800°C to 1200°C. Figures 2.5 and 2.6 show the effects of steam partial pressure on reactivity at X=0.5, for temperatures of 800–1000°C of the two chars, Original Char B and Slurry Char B, respectively. Increasing steam pressure from 10 to 51 kPa (a factor of 5.1) raised the reactivity typically by about 80%. 0 0.002 0.004 0.006 0 0.2 0.4 0.6 0.8 1 X r, s -1 Char A Slurry Char A, 10000°C/s Slurry Char A, 1000°C/s Slurry Char A, 100°C/s Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 41 Figure 2.4 Reactivity of chars at X=0.5; steam partial pressure at: (a) 10 kPa, (b) 30 kPa, and (c) 51 kPa 0.0001 0.001 0.01 0.1 0.6 0.7 0.8 0.9 1 1/T ×10 3 , K -1 r , s- 1 Original Char B Slurry Char B 10 kPa steam (a) 0.0001 0.001 0.01 0.1 1 0.6 0.7 0.8 0.9 1 1/T ×10 3 , K -1 r , s- 1 Original Char B Slurry Char B (b) 30 kPa steam 0.0001 0.001 0.01 0.1 1 0.6 0.7 0.8 0.9 1 1/T ×10 3 , K -1 r , s- 1 Original Char B Slurry Char B 51 kPa steam (c) Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 42 Figure 2.5 Original Char B steam gasification reactivity, steam effect (X=0.5); continuous lines show n-th order reaction model Figure 2.6 Slurry Char B reactivity as a function of steam partial pressure and temperature (X=0.5); continuous lines show n-th order reaction model 0.0001 0.001 0.01 0.1 10 100 Steam pressure, kPa r , s- 1 1000°C 900°C 800°C 0.0001 0.001 0.01 0.1 10 100 Steam pressure, kPa r , s- 1 1000°C 900°C 800°C Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 43 2.4.3 n-th order kinetics The kinetic parameters for the n-th order kinetic model were determined for the Slurry Char B and Original Char B, which were pyrolyzed at the heating rate of 1000°C/s. Data obtained from the gasification at 800–1000°C and steam partial pressure at 10–51 kPa were used for determining the parameters, k0, E and n. Parameters obtained from linearized model fitting and non-linear fitting are close. The results are compared in Table 2.4 with values from the literature. Activation energies and frequency factors obtained in this study are similar to those of wood chars obtained by Barrio et.al. for 750–950°C and PH2O=10–51 kPa (Barrio et al., 2001), while the reaction orders were somewhat smaller. Compared with Kojima et al. for 850–950°C and PH2O=0–58 kPa (Kojima et al., 1993), activation energy in the present work was higher, but reaction order was similar. As can be seen, those parameters from the literature are obtained from a similar range of temperature and steam pressure to those in the present study, and are therefore roughly comparable. The discrepancies may come from uncertainty of fitting method, or from the differences in char origin. Figures 2.7 and 2.8 show Arrhenius plots of the steam gasification for Original Char B and Slurry Char B. The plot of ln k vs 1/T(K) was linear up to 1000°C in a similar manner for both chars. Above 1000°C, the rate became less sensitive to temperature, which is attributed to increased diffusional resistance and/or H2 inhibition due to increased H2 production by steam gasification at the higher temperatures. Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 44 Table 2.4 Kinetic parameters determined and literature value for comparison Reference Char origin E (kJ mol -1 ) k0 (s -1 Pa -n ) n This work (800– 1000°C) Fast pyrolysis of wood 235 ± 12 6.5×10 5 0.41 ± 0.13 (9×10 4–5×106) Least-square fitting of linearized model Bio-oil/char slurry 219 ± 13 3.4×10 5 0.34 ± 0.14 (4×10 4–3×106) This work (800– 1000°C) Fast pyrolysis of wood 236 4.5×10 5 0.45 Non-linear fitting Bio-oil/char slurry 218 2.7×10 5 0.34 Barrio et al., 2001 (750–950°C) Birch 237 3.30×10 6 ± 6×10 4* 0.57 ± 0.03 Beech 211 2.15×10 5 ± 1×10 5* 0.51 ± 0.05 Kojima et al., 1993 (850–950°C) Sawdust 179 1773 0.41 * The units were converted to s -1 Pa -n Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 45 Figure 2.7 Arrhenius plot of Original Char B steam gasification (X=0.5); dotted line indicates linear relationship for 800–1000°C Figure 2.8 Arrhenius plot of Slurry Char B steam gasification (X=0.5); dotted line indicates linear relationship for 800–1000°C -13 -12 -11 -10 -9 -8 -7 -6 -5 0.6 0.7 0.8 0.9 1 1/T ×10 3 , K -1 ln k 51 kPa steam 30 kPa steam 10 kPa steam -13 -12 -11 -10 -9 -8 -7 -6 -5 0.6 0.7 0.8 0.9 1 1/T ×10 3 , K -1 ln k 51 kPa steam 30 kPa steam 10 kPa steam Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 46 2.5 Conclusion Steam gasification study of char originally produced with bio-oil, and char produced by pyrolysis of bio-oil/char slurry leads to the following conclusions: (1) At 900°C, as conversion increased, the reactivity of Slurry Char became less compared to that of Original Char. This deactivation was consistent with surface area change by rapid pyrolysis. At X=0.5 and 900–1200°C, the reactivity of Slurry Char was very close to that of Original Char. At 800°C, the lowest gasification temperature tested, Slurry Char was more reactive than Original Char. (2) Raising the pyrolysis heating rate of bio-oil/char slurry resulted in a higher reactivity of Slurry Char. Therefore heating rate of bio-oil/char slurry injected into a steam gasification reactor is an important factor for the gasifier system design. (3) The kinetic parameters of steam gasification of Slurry Char and Original Char according to the n-th order kinetic model were determined at X=0.5: E=235 kJ/mol, k0=1.69×10 6 and n=0.41 for Slurry Char B, and E=219 kJ/mol, k0=7.38×10 5 and n=0.34 for Original Char B. These activation energies and reaction orders are similar to respective values for wood char found in the literature. (4) At temperatures above 1000°C, the temperature sensitivity of the reactivity decreased, presumably due to the importance of diffusional resistances. Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 47 2.6 References Barrio, M., Gøbel, B., Risnes, H., Henriksen, U., Hustad, J. E., and Sørensen, L. H. (2001) Steam gasification of wood char and the effect of hydrogen inhibition on the chemical kinetics, in: Bridgwater, A. V., (Ed.), Progress in Thermochemical Biomass Conversion, Blackwell Science, Oxford, vol.1, pp. 32-46. Basagiannis, A. C., and Verykios, S. E. (2007) Steam reforming of the aqueous fraction of bio- oil over structured Ru/MgO/Al2O3 catalysts. Catalysis Today 127, 256-264. Bridgwater, A. V., Czernik, S., and Piskorz, J. (2001) An overview of fast pyrolysis, in: Bridgwater, A. V. (Ed.), Progress in Thermochemical Biomass Conversion, Blackwell Science, Oxford, vol.2, pp. 977-997. Czernik, S., French, R., Feik, C., and Chornet, E. (1999) Hydrogen from biomass via fast pyrolysis/catalytic steam reforming process, in: The 1999 U.S DOE Hydrogen Program Review, NREL/CP-570-26938, National Renewable Energy Laboratory, Golden, Colorado. Czernik, S., French, R., Feik, C., and Chornet, E. (2002) Hydrogen by catalytic steam reforming of liquid byproducts from biomass thermoconversion processes. Industrial & Engineering Chemistry Research 41, 4209-4215. Czernik, S., Evans, R., and French, R. (2007) Hydrogen from biomass-production by steam reforming of biomass pyrolysis oil. Catalysis Today 129, 265-268. Davidian, T., Guilhaume, N., Iojoiu, E., Provendier, H., and Mirodatos, C. (2007) Hydrogen production from crude pyrolysis oil by a sequential catalytic process. Applied Catalysis B: Environmental 73, 116-127. Dinjus, E., Henrich, E., and Weirich, F. (2004) A two stage process for synfuel from biomass. in: IEA bioenergy agreement task 33: Thermal gasification of biomass, task meeting, Vienna, May 3–5. Domine, M. E., Iojoiu, E. E., Davidian, T., Guilhaume, N., and Mirodatos, C. (2008) Hydrogen production from biomass-derived oil over monolithic Pt- and Rh-based catalysts using steam reforming and sequential cracking processes Catalysis Today 133-135, 565-573. Garcia, L., French, R., Czernik, S., and Chornet, E. (2000) Catalytic steam reforming of bio-oils for the production of hydrogen: effects of catalyst composition. Applied Catalysis, A: General 201, 225-239. Chapter 2. Steam Gasification Reactivity of Char from Rapid Pyrolysis of Bio-oil/Char Slurry 48 Henrich, E. (2005) Clean syngas from biomass pressurized entrained flow gasification of slurries from fast pyrolysis, in: SYNBIOS - Second generation automotive biofuel conference, Stockholm, Sweden, May 18–20. Iojoiu, E. E., Domine, M. E., Davidian, T., Guilhaume, N., and Mirodatos, C. (2007) Hydrogen production by sequential cracking of biomass-derived pyrolysis oil over noble metal catalysts supported on ceria-zirconia. Applied Catalysis A: General 323, 147-161. Kechagiopoulos, P. N., Voutetakis, S. S., Lemonidou, A. A., and Vasalos, I. A. (2006) Hydrogen production via steam reforming of the aqueous phase of bio-oil in a fixed bed reactor. Energy & Fuels 20, 2155-2163. Kojima, T., Assavadakorn, P., and Furusawa, T. (1993) Measurement and evaluation of gasification kinetics of sawdust char with steam in an experimental fluidized bed. Fuel Processing Technology 36, 201-207. Marquevich, M., Czernik, S., Chornet, E., and Montane, D. (1999) Hydrogen from biomass: Steam reforming of model compounds of fast-pyrolysis oil. Energy Fuels 13, 1160-1166. Magrini-Bair, K., Czernik, S., French, R., Parent, Y., Ritland, M., and Chornet, E. (2002) Fluidizable catalysts for producing hydrogen by steam reforming biomass pyrolysis liquids, in: the 2002 U.S. DOE Hydrogen Program Review, NREL/CP-610-32405, National Renewable Energy Laboratory, Golden, Colorado. Rioche, C., Kulkarni, S., Meunier, F. C., Breen, J. P., and Burch, R. (2005) Steam reforming of model compounds and fast pyrolysis bio-oil on supported noble metal catalysts. Applied Catalysis B: Environmental 61, 130-139. van Rossum, G., Kersten, S. R. A., and van Swaaij, W. P. M. (2007) Catalytic and noncatalytic gasification of pyrolysis oil. Industrial & Engineering Chemistry Research 46, 3959-3967. Wu, C.; Huang, Q.; Sui, M.; Yan, Y.; Wang, F. (2008) Hydrogen production via catalytic steam reforming of fast pyrolysis bio-oil in a two-stage fixed bed reactor system. Fuel Processing Technology 89, 1306-1316. Wang, D., Czernik, S., Montane, D., Mann, M., and Chornet, E. (1997) Biomass to hydrogen via fast pyrolysis and catalytic steam reforming of the pyrolysis oil or its fractions. Industrial & Engineering Chemistry Research 36, 1507-1518. Wang, D., Czernik, S., and Chornet, E. (1998) Production of hydrogen from biomass by catalytic steam reforming of fast pyrolysis oils. Energy Fuels 12, 19-24. 49 CHAPTER 3 Steam Gasification of Bio-Oil and Bio-Oil/Char Slurry in a Fluidized Bed Reactor 2 3.1 Introduction Biomass is a promising renewable resource which can contribute to the substitution of fossil resources over many parts of the world. It can be converted to transportation fuels and chemicals by thermochemical or biological processes. Production of synthesis gas from biomass is a key first step in the thermochemical route. Gasification of biomass may be carried out using either solid primary biomass or secondary products derived from pyrolysis processes. Pyrolysis of biomass yields vapours, gas and char. In rapid pyrolysis processes, biomass is heated up in the absence of oxygen to around 500°C within a few seconds and decomposed to gas, vapour and char. The condensed liquid product from the vapour, bio-oil, is a dark brown-coloured liquid of similar elemental composition to the feedstock biomass material (Bridgwater et al., 2001). As a high density liquid (typically 1200 kg/m 3 ), bio-oil can be readily stored, and pumped, leading to reduced storage and transportation cost compared to dry biomass. When mixed with the by- product char from the same process, a bio-oil/char slurry of density 1300 kg/m 3 can be prepared (at 80 wt% bio-oil/20 wt% char). The slurry has an energy density 24% higher than the original biomass fed to the pyrolyzer. As energy dense slurry reduces not only transport cost but also traffic density substituting truck transport by rail transport, a concept of many local pyrolysis facilities connected with a large scale centralized fuel synthesis plant has been studied (Henrich et al., 2009). Possibly due to the difficulty in gasification of heavy compounds, whole bio-oil 2 A version of this chapter will be submitted for publication. Sakaguchi, M., Watkinson, A. P. and Ellis, N. Steam gasification of bio-oil and bio-oil/char slurry in a fluidized bed reactor. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 50 steam gasification research has started only recently. Despite the extensive works on steam gasification of bio-oil (e.g. Czernik et al., 2007; Marda et al., 2009; van Rossum et al., 2007), research for bio-oil/char slurry is limited to studies of oxygen-blown, pressurized, entrained-flow gasification at 1200–1600°C (Dinjus et al., 2004; Henrich, 2005). There has been no study on pure steam gasification of bio-oil/char slurry reported. Partial oxidation, conducted by introducing pure oxygen or air, results in decomposition of the feedstock as well as supplying heat for endothermic gasification reaction. Compared to partial oxidation, pure steam gasification can increase synthesis gas yield by preventing combustion of synthesis gas by introduced oxygen. In the present study, the steam gasification of bio-oil/char slurry was investigated using a lab-scale fluidized bed reactor filled with either Ni-based naphtha steam reforming catalyst, or silica sand. The components and yield of the product gas, and carbon conversion to gas were compared with those from bio-oil. The experimental results from both the slurry and bio-oil were compared with the values predicted by an equilibrium model, to determine how close the product gas was to the equilibrium at each experimental condition. Partial oxidation (air gasification) of the bio-oil and the slurry is reported separately (Chapter 4). 3.2 Experimental equipment and methodology Bio-oil and char, produced from wood in a commercial-scale fast pyrolysis plant, were provided by Dynamotive Energy Systems Corporation of Canada. Char was the by-product of the bio-oil production, in which it is separated from hot pyrolyzed gas by a cyclone. Bio-oil and char were produced from the same feedstock at the same plant. Proximate analysis of the char and the ultimate analysis of the char and the bio-oil are shown in Tables 3.1 and 3.2, respectively. Water content of the bio-oil was 25.2 wt%. Bio-oil/char slurry was prepared by mixing 80 wt% Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 51 bio-oil and 20 wt% char. Prior to mixing, char was crushed and sieved to a particle size below 38 m. Particle size of the char was 5.9 m (median), measured using a Mastersizer 2000 (Malvern Instruments). The bio-oil and the prepared slurry were stored in sealed containers at 5°C. Table 3.1 Proximate analysis of Original Char in wt% Moisture Volatile Matter (dry basis) Fixed Carbon (dry basis) Ash (dry basis) 2.3 27.1 67.1 5.8 Table 3.2 Ultimate analyses of bio-oil and Original Char in wt%; bio-oil is shown in the wet basis and char is shown in the dry ash free basis Sample C H N S O (by diff.) Bio-oil 42.5 7.2 <0.3 <0.3 49.7 Char 76.5 3.7 <0.3 <0.3 19.2 *Ultimate analysis was done by Canadian Microanalytical Service Ltd., Delta, British Columbia 3.2.1 Fluidized bed material A commercial naphtha steam-reforming catalyst, RK-212, from Haldor-Topsoe was used as bed material for catalytic steam gasification. Silica sand (from TEC MINERALS, Eagle Lake, Texas) was also used as a bed material for non-catalytic steam gasification. Metal analysis of both the materials is shown in Table 3.3. Both catalyst and sand were crushed and sieved into the particle size between 180 and 355 m. The bulk and particle densities, Archimedes’ numbers and the ranges of calculated minimum fluidization velocity, Umf, are shown in Table 3.4. Both particles are around the boundary of group A and B particles on Geldart’s particle classification. The catalyst and the sand surfaces were characterized by scanning electron microscopy (SEM) after the steam gasification experiments. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 52 Table 3.3 Metal analysis of the catalyst (RK-212) and the sand (*analyzed by whole rock fusion analysis, measured by ICP) RK-212 Sand Unit Al2O3 60.99 0.64 wt% CaO 3.36 0.04 Fe2O3 0.15 0.15 K2O 1.32 0.27 MgO 13.98 0.02 MnO <0.01 <0.01 Na2O 0.85 0.08 P2O5 0.04 0.01 SO3 0.14 0.01 SiO2 2.50 98.14 TiO2 0.01 0.05 Ba 486 167 ppm(wt) Cr 8 2 Ni 140200 41 Sr 74 14 V <1 4 *L.O.I. at 1000°C 2.00 0.26 wt% SUM 99.36 99.67 wt% *Analysis was done by Loring Laboratories Ltd., Calgary, Alberta. **L.O.I.: Loss on ignition after 30 min fusion at 1000°C. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 53 Table 3.4 Particle and fluidization properties of catalyst and sand in the steam gasification experiments (particle size: dp=180–355 m; gas viscosity: =3.7–4.5×10 5 Pa·s; gas density: g=0.2 kg/m 3 ) Bulk density (g/cm 3 ) Particle density, p (g/cm 3 ) Ar Umf [m/s] Catalyst 1.3 3.7 21–240 0.02–0.09 Sand 1.7 2.7 16–180 0.02–0.07 The minimum fluidization velocity was calculated as, 𝑈mf = 0.00075 (𝜌p − 𝜌g)g𝑑p 2 𝜇 (simplified form when Ar<10 3 (Wen and Yu, 1966; Grace, 1982)) Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 54 3.2.2 Gasification setup Steam gasification experiments were carried out in a lab-scale fluidized bed reactor as shown in Figure 3.1. The reactor was made of 310 stainless steel, and comprised of 3-inch diameter (nominal) pipe (I.D.=77.9 mm, h≈800 mm) with a perforated plate distributor. It was surrounded by a 9 kW furnace which supplies heat of reaction for the endothermic steam gasification reaction. The reactor was charged with 0.6 L (bulk) of either the catalyst or the sand, which corresponded to a fixed bed heightof~0.13 m for both bed materials. The bed was fluidized by superheated steam generated by a steam generator, which is comprised of a furnace of 7 kW output and a 2.5 inch diameter (nominal) 316L stainless steel pipe (I.D.=63 mm and length=1 m) filled with ceramic Raschig rings. Water was fed into the steam generator by a diaphragm pump. The bio-oil and slurry were fed from the side of the fluidized bed by a peristaltic pump through an atomizer nozzle which was fully surrounded by a cooling jacket to keep the feedstock temperature less than 80°C to avoid plugging by thermal decomposition. An aircap for airbrush (VLA-3 aircap with VLB aircap body, Paasche Airbrush Co.) was installed as the atomizer nozzle on a 6.35 mm O.D. (4.57 mm I.D.) 316 stainless tubing (outer tube), and 3.18 mm O.D. (1.40 mm I.D.) 316 stainless tube was placed inside to feed the bio-oil and slurry. Atomizing gas (N2) was fed in the outer tube, atomizing feedstock material at the nozzle. The schematic for the atomizer is included in Appendix C. Various configurations and tests were conducted with the bio-oil and the slurry to ensure proper atomization. The feedstock was sprayed at the end of the atomizer through a 1.6 mm diameter hole with nitrogen. Excess steam in the product gas was condensed and separated by a condenser. Fine char and catalyst particles which could be generated in the reactor were captured Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 55 by an internal cyclone in the reactor, and a filter after the condenser. Product gas flow was measured by a volumetric flow meter combined with a thermocouple and a pressure transducer with which the product mass flow rate was determined. The concentrations of H2, N2, CO, CO2 and CH4 were measured by micro gas chromatograph CP-4900 (Varian, Inc.) with COX column and thermal conductivity detector, and C2–C4 components (acetylene, ethylene, ethane, propene, propane, iso-butane, 1-butene and butane) were measured by gas chromatograph/mass spectroscopy, GC-3800/MS-4000 (Varian, Inc.) with a capillary column, CP-PoraBOND Q fused silica, 25 m x 0.25 mm. Temperatures and product gas flow rates were recorded during experiments. BET surface areas of unused and used catalysts both for bio-oil and slurry gasification were measured with N2 at 77 K via a multi-point method used with a Micrometritics ASAP2020 surface area analyzer. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 56 Figure 3.1 Schematic of the steam gasification fluidized bed experimental apparatus Condenser Fluidized bed reactor Condensate collector Steam generator Cooling jacket + Atomizer Micro-GC Filter Flow meter After burner To Vent Air Pump Rotameters N2 Pump Sampling for GC/MS Bio-oil Slurry H2O H2 Air N2 Rotameters Ice trap To Vent Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 57 3.2.3 Experimental procedure and calculations When the catalyst was used as a bed material, 50% H2 – 50% N2 mixture was first introduced after two hours at 400°C for activation. To atomize the bio-oil and slurry, N2 was injected as an atomizing gas. When the sand was used as a bed material, the reactor was heated up to the gasification temperature with air/N2 injection. The bio-oil and the slurry were fed at 2.7–5.3 g/min and 3.3–3.5 g/min, respectively, with 12 L/min STP of nitrogen. Water was introduced to the steam generator at the feed rates of 6.2–19.4 g/min and 12.9–13.8 g/min for bio-oil and slurry steam gasification, respectively. The steam temperature entering the reactor was in the range of 700–800°C, and the superficial gas velocity of 7–10Umf for the catalyst, and 4–10Umf for the sand. As the feed changes to gas, U at the exit of the reactor is always larger than that at entrance. The ratios for the product gas in the reactor were U/Umf=9–16 for the catalyst and U/Umf=7–15 for the sand. It was ensured that the experimental conditions were set for bubbling fluidization to occur. After each steam gasification experiment, methanol was introduced to the atomizer to clean the nozzle, and then an air/N2 mixture was introduced to remove carbon residue in the reactor which could possibly accumulate during the experiment. In the present study, the hydrogen and carbon yields are described in mole% of elemental hydrogen and carbon in each component of the product gas produced from the feedstock without inherent water: 1) H2, CH4 and C2–C4 components shown above for the hydrogen yield, and 2) CO, CO2, CH4 and C2–C4 components for the carbon yield. The carbon conversion to gas is the sum of the carbon yield of each product gas component. Unconverted carbon in the gasifier is calculated from the carbon balance. Due to the unconverted carbon accumulation, a true steady Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 58 state cannot be achieved. However, since product gas yield during c.a. 1 hour successive duration was stable, carbon balance calculation was applied as if the process was in steady state. Bio-oil and slurry are gasified by steam according to, C𝑥H𝑦O𝑧 + 𝑥 − 𝑧 H2O → 𝑥CO + 𝑥 + 𝑦 2 − 𝑧 H2 (3.1) where CxHyOz is the empirical formula of bio-oil or slurry. For the bio-oil, x=1, y=2.03 and z=0.88, whereas for the slurry, x=1, y=1.60 and z=0.67, including contained water. Hydrogen yields larger than 100% can be possible when the steam gasification reaction is followed by the water-gas shift reaction, CO + H2O ⇄ H2 + CO2 (3.2) by which CO reacts with steam yielding more H2. When the hydrogen yield is more than 100%, the exceeded portion of hydrogen is from the steam fed to the system. Steam conversion is the percentage of steam, the sum of fed water into the reactor and contained water in the feedstock, consumed by the steam gasification reaction and the water-gas shift reaction, and is calculated by dividing increased atomic hydrogen in the product gas by the sum of atomic hydrogen contained in the water in the feedstock and in the fed water. The steam to carbon ratio (H2O/C) is the molar ratio of the steam plus the inherent water of the feedstock (bio-oil water content is 25.2 wt%) introduced to the reactor and the carbon in the feedstock. The gas hourly space velocity, GC1HSV is defined as the volume of methane, assuming 100% of carbon in the feedstock is converted to methane, at standard temperature and pressure per unit bulk volume of catalyst per hour. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 59 3.3 Results and discussion Table 3.5 shows a typical product gas composition and heating value from steam gasification of bio-oil and bio-oil/char slurry. The nitrogen concentration was c.a. 33% from atomizing the feedstock, and the steam concentration was c.a. 50%. Dry and nitrogen free composition were compared with values in the literature shown in Table 3.6 (Czernik et al., 2007; van Rossum et al., 2007) obtained from similar and different reactors, respectively, and catalysts as those used in the present study. The H2 produced is close to that in (van Rossum et al., 2007)., and significantly below that in (Czernik et al., 2007). Table 3.5 Product gas composition (in mol%) and heating value from steam gasification of the bio-oil and the slurry with the catalyst and the sand at T≈800°C, H2O/C≈5.5, and GC1HSV≈340 h -1 ; wet with nitrogen and dry nitrogen free basis Bed material Feed (Run name) Basis H2 CO CO2 CH4 C2+ N2 H2O* HHV- MJ/m 3 Sand Bio-oil (SGOC28-2) Wet, N2 included 3.7 3.4 1.3 1.2 0.4 32.6 57 3.1 Dry, N2 free 35 33 13 11 4 - - 15.8 Slurry (SGOC-28-1) Wet, N2 included 3.7 2.6 1.5 0.9 0.2 33.8 57 2.7 Dry, N2 free 39 28 16 10 2 - - 12.4 Catalyst Bio-oil (SGOC22-2) Wet, N2 included 13.1 2.4 5.5 0.7 0.1 32.3 45 3.9 Dry, N2 free 57 10 24 3 0 - - 9.4 Slurry (SGOC22-1) Wet, N2 included 11.6 1.6 4.9 0.2 0.0 33.8 47 3.1 Dry, N2 free 59 8 25 1 0 - - 8.3 *H2O concentration was calculated by H elemental balance. Due to measurement errors and undetectable components (i.e., water) of the micro-GC, the total concentration is < 100%. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 60 Table 3.6 Product gas composition (in mol%, dry N2 free basis) from steam gasification of bio-oil found in the literature Reference Bed material Feed H2O/C H2 CO CO2 CH4 C2+ Czernik et al., 2007, fluidized bed reactor Ni based catalyst Bio-oil 5.8 ~70 ~9 ~20 ~1 n.a. Van Rossum et al., 2007, spouted bed reactor Sand Bio-oil (pine) 1.9 26.8 44.7 5.6 15.6 6.7 Ni-K/La on alumina Bio-oil (beech) 3.1 52.8 10.2 25.1 9.1 1.4 KATALCO 46 (for naphtha reforming) Bio-oil (beech) 3.2 55.5 19.3 19.0 5.4 1.0 This work Sand Bio-oil 5.5 35 33 13 11 4 Catalyst Bio-oil 5.5 57 10 24 3 0 Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 61 3.3.1 Effect of catalysis and temperature on bio-oil steam gasification Figure 3.2 shows the hydrogen and carbon yields from the bio-oil steam gasification at H2O/C≈5.5, GC1HSV≈340 h -1 , and three different temperatures between 747 and 832°C for the non-catalytic steam gasification, and 725 to 803°C for the catalytic steam gasification. The difference between 100% and the total carbon conversion shows the amount of residual carbon and tar generated by the reaction. After catalytic steam gasification experiments, there was no evidence of tar formation downstream of the reactor, while tar was always found after non- catalytic steam gasification experiments. Under the catalytic conditions, the H2 yield and CO2 yield were significantly greater than those obtained under the non-catalytic conditions (sand), and the hydrocarbons and CO yields at the catalytic conditions were less than those for non- catalytic conditions. This significant change in the product gas components yields was caused by: 1) the catalysis of the steam gasification (Reaction (3.1)) by which hydrocarbons react with H2O yielding H2, CO and CO2; and 2) water-gas shift reaction (Reaction (3.2)) by which CO reacts with H2O yielding H2 and CO2. In addition, the total carbon conversion to gas was higher under the catalytic steam gasification than under the non-catalytic steam gasification (sand). This indicates that the injected bio-oil was evaporated and successfully decomposed and/or steam gasified better under the catalytic conditions than under the non-catalytic conditions. With increasing temperature, the H2 yield and the CO + CO2 yield, leading to the total carbon conversion to gas, increased under the non-catalytic steam gasification. However, under catalytic steam gasification, no clear relationships were found between both the carbon and hydrogen yields, and the gasification temperature. The hydrocarbon yield was not clearly affected by the Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 62 gasification temperature under the non-catalytic conditions either. Figure 3.3 shows the steam conversion at steam gasification of the bio-oil and the slurry with catalyst and sand. Catalyst strongly promoted reactions involving steam, while little water was involved in steam gasification under non-catalytic conditions. Thus, the gasification process under the present non- catalytic conditions is mostly thermal decomposition, without involving the water-gas shift reaction and the steam gasification reaction. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 63 Figure 3.2 Effect of catalysis on: a) carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4) ; and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) on the dry feed stock basis; under steam gasification, H2O/C≈5.5, GC1HSV ≈ 340 h -1 Figure 3.3 Steam conversion by steam gasification of the bio-oil and the slurry under catalytic and non-catalytic conditions 0 20 40 60 80 100 Sand Sand Sand Catalyst Catalyst Catalyst 747 °C 790 °C 832 °C 725 °C 773 °C 803 °C C a rb o n y ie ld [ a to m ic m o l % ] CO CO2 CH4 C2-C4 a 0 100 200 300 400 Sand Sand Sand Catalyst Catalyst Catalyst 747 °C 790 °C 832 °C 725 °C 773 °C 803 °C H y d ro g e n y ie ld [ a to m ic m o l% ] CH4 C2-C4 H2 b 0 5 10 15 20 Sand Sand Catalyst Catalyst Bio-oil Slurry Bio-oil Slurry 832 °C 836 °C 803 °C 815 °C S te a m c o n v e rs io n [ % ] Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 64 3.3.2 Effect of space velocity and H2O/C ratio under non-catalytic steam gasification Figure 3.4 shows the effect of the space velocity of the bio-oil on the hydrogen and carbon yields at three different GC1HSV values between 210–400 h -1 (changed by feedstock feed rate from 2.7 to 5.3 g/h, keeping the same volume of the sand), T≈790°C and H2O/C≈5.5. Figure 3.5 shows the effect of the steam to carbon ratio on the hydrogen and carbon yields at three different H2O/C between 2.7–7.5, T≈800°C and GC1HSV≈320 h -1 . Due to measurement error of the micro-GC, the error range of hydrogen yield is much wider than that for carbon yield. Under the bio-oil steam gasification conditions set by the present study, both the space velocity of the feedstock and the steam to carbon ratio did not clearly affect the product gas yield and composition. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 65 Figure 3.4 Effect of space velocity on: a) carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) on the dry feed stock basis; at T≈800°C and GC1HSV≈320 h -1 under non-catalytic steam gasification Figure 3.5 The effect of steam to carbon ratio on: a) carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2–C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2–C4) ; at H2O/C≈5.5 and T≈790°C under non- catalytic steam gasification 0 10 20 30 40 50 0 100 200 300 400 500 C a rb o n y ie ld [ a to m ic m o l% ] GC1HSV [h -1] CO CO2 CH4 C2-4 a 0 20 40 60 80 100 0 100 200 300 400 500 H y d ro g e n y ie ld [ a to m ic m o l% ] GC1HSV [h -1] H2 CH4 C2-4 b 0 10 20 30 40 50 0 2 4 6 8 C a rb o n y ie ld [ a to m ic m o l% ] H2O/C CO CO2 CH4 C2-4 a 0 20 40 60 80 100 0 2 4 6 8 H y d ro g e n y ie ld [ a to m ic m o l% ] H2O/C H2 CH4 C2-4 b Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 66 3.3.3 Effect of feedstock and temperature on the product gas yield under catalytic steam gasification Figure 3.6 shows the hydrogen and carbon yields from bio-oil and slurry catalytic steam gasification at H2O/C≈5.5, GC1HSV≈340 h -1 , and three temperatures between 725 and 803°C for bio-oil steam gasification, and three temperatures between 755 and 815°C for the slurry steam gasification. The carbon conversion to gas, and especially the CO yield from the slurry steam gasification was less than from the bio-oil steam gasification. The slurry yielded more unconverted carbon under steam gasification than the bio-oil, probably because the slurry initially contained 20 wt% char, which was 31% of total carbon content in the slurry. This might easily become residual carbon due to the lower reactivity of the char than for the gaseous components involved in the reaction system. However, the total carbon conversion differences between slurry and bio-oil decreased with increasing temperature (by: 24% at 725–755°C; 19% at 773–784°C; and 14% at and 803–815°C). These decreased differences in carbon conversion were mainly caused by increasing carbon conversion of slurry with increasing temperature. As the carbon from the char was 31% of the total carbon content in the slurry, the unconverted carbon at the low temperature of 755°C seems to be unconverted char with residue from bio-oil, while that at the high temperature of 815°C may mainly from the originally contained char. In addition, the carbon conversions to gas from the bio-oil were similar at different temperatures in the 725-803°C range. This shows that the char promoted generation of residual carbon at low temperature, but not at high temperature. Figure 3.7 shows the effects of catalysis and feedstock on the carbon and hydrogen yields. Comparing the catalytic and non- catalytic (sand) conditions, the total carbon conversion under the catalytic conditions was higher Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 67 than that under non-catalytic conditions by c.a. 20%: catalyst significantly suppressed the production of residual carbon. The carbon conversion to gas from the slurry was about 70%. It seems that residual carbon was highly suppressed, but char remained unreacted, as gas produced from the char would contribute to the total carbon conversion to gas by 0.1% (assuming no residual carbon accumulation) according to the char’s steam gasification reactivity (Chapter 2). Therefore, a high gasification temperature is required to suppress residual carbon generation, but it is difficult to convert the char effectively by steam. Thus, for continuous steam gasification, this residual carbon should be removed, for example, in a dual-bed gasifier (Pfeifer et al., 2009) in which the carbon residue is transported to a separate combustion process with the bed material to be burnt and recycled back to the steam gasification reactor. The heat of combustion of the carbon residue is essentially transported back to the gasifier by the enthalpy of the bed material. This helps supply the heat for the endothermic condition of the steam gasification reaction, and reduce external energy input. There were no clear relationships between the hydrogen yield and the gasification temperature from the experimental results in the present study. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 68 Figure 3.6 Effect of temperature on: a) carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4), under catalytic steam gasification at H2O/C≈5.5, and GC1HSV≈340 h -1 Figure 3.7 Comparison of feedstock under catalytic and non-catalytic steam gasification on: a) carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) at H2O/C≈5.6 and GC1HSV≈320 h -1 0 20 40 60 80 100 Bio-oil Bio-oil Bio-oil Slurry Slurry Slurry 725 °C 773 °C 803 °C 755 °C 784 °C 815 °C C a rb o n y ie ld [ a to m ic m o l % ] CO CO2 CH4 C2-C4 a 0 100 200 300 400 Bio-oil Bio-oil Bio-oil Slurry Slurry Slurry 725 °C 773 °C 803 °C 755 °C 784 °C 815 °C H y d ro g e n y ie ld [ a to m ic m o l% ] H2 CH4 C2-C4 b 0 20 40 60 80 100 Sand Sand Catalyst Catalyst Bio-oil Slurry Bio-oil Slurry 832 °C 836 °C 803 °C 815 °C C a rb o n y ie ld [ a to m ic m o l % ] CO CO2 CH4 C2-C4a 0 100 200 300 400 Sand Sand Catalyst Catalyst Bio-oil Slurry Bio-oil Slurry 832 °C 836 °C 803 °C 815 °C H y d ro g e n y ie ld [ a to m ic m o l% ] H2 CH4 C2-C4 b Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 69 3.3.4 Comparison with thermodynamic equilibrium The data were compared with values calculated assuming thermodynamic equilibrium. To predict the product gas composition, the modeling approach for gasification of carbonaceous materials of Li et al. (2001) was applied. In the model, the system which included C, H, O, N and S, was simplified to 42 gaseous species and two solid species. The model was solved by minimizing Gibbs free energy of the system using the RAND algorithm. To take kinetic effects into account, such as unconverted carbon and hydrocarbons which influence real processes by kinetics and/or mass transfer, elemental abundances in the steam gasification system were adjusted, as done by Li et al. (2004): unconverted carbon, and carbon and hydrogen in hydrocarbons in the product gas were initially withdrawn from the elemental abundances before the equilibrium calculation. Then, the hydrocarbons were added to the result of the equilibrium calculation. The experiments of Li et al. used different feedstocks (dry biomass), a different circulating fluid bed gasifier, and were limited to partial oxidation where methane was the only hydrocarbon reported. Rather than use their empirical equations, in the present study the amounts of unconverted carbon and hydrocarbons were substituted one by one using experimental data. The present model was validated by comparing predictions for a simple C-H- O system, the H2O + C(s) reaction with those reported by Massey (1979). The discrepancy was less than 1%. Figure 3.8 compares the H2 and CO yields between data from the present work and values from references (Czernik et al., 2007; van Rossum et al., 2007), and kinetic modified model-predicted values for both obtained data and values from the references. The H2 yield was close to that predicted at equilibrium for both the bio-oil and the slurry under the catalytic steam gasification conditions, whereas the non-catalytic steam gasification yielded much less H2 Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 70 (Figure 3.8b). The CO yield was greater under non-catalytic conditions and less under catalytic conditions due to the catalysis of the water-gas shift reaction, yielding H2 and consuming CO, making the reaction system close to equilibrium under excess amount of steam (Figure 3.8a). Therefore, the product gas yield from catalytic steam gasification is predictable reasonably well once the parameters for the kinetic modified model, carbon conversion and hydrocarbon yield, are determined empirically from the actual gasification system. The value from Czernik et al. (2007) was close to the equilibrium model, while data from van Rossum et al. (2007) differed from equilibrium, even with catalyst, probably due to the different reactor type, i.e., a spouted bed reactor which could affect the kinetic modification. Under non-catalytic conditions, the carbon yield as CO was much higher and the hydrogen yield as H2 was much lower. This is the same tendency as data from the present study. From the comparison, it is found that application of the kinetically-modified model to the present study resulted in good agreement, but this was not the case for the values from other researchers; model validity for different reactor types should be studied in more detail. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 71 Figure 3.8 a) Carbon yield as CO; and b) hydrogen yield as H2, compared with kinetically modified equilibrium model (725–836°C, H2O/C≈5.5, GC1HSV≈330 h -1 , ●: bio- oil – catalytic, ■: slurry – catalytic, ○: bio-oil – non-catalytic, □: slurry – non- catalytic, ♦: reference (Czernik et al., 2007) bio-oil – catalytic, ▲: reference (van Rossum et al., 2007) bio-oil – catalytic, ∆: reference (van Rossum et al., 2007) bio-oil – non-catalytic) a 0 10 20 30 40 0 10 20 30 40 C ar b o n y ie ld a s C O ( at o m ic m o l% ) Carbon yield as CO, modified equilibrium model (atomic mol%) b 0 100 200 300 400 0 100 200 300 400 H y d ro g en y ie ld a s H 2 (a to m ic m o l% ) Hydrogen yield as H2, modified equilibrium model (atomic mol%) Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 72 3.3.5 Catalyst deactivation and attrition of bed material A test of catalyst de-activation effects was done as follows. An experimental run of bio- oil partial oxidation was first conducted with catalyst. Then three runs were carried out at different conditions. After each run the usual burn-out of combustible material on the catalyst was done. Then the conditions of the first run were repeated. Figure 3.9 shows catalyst deactivation behaviour in the carbon and hydrogen yields from bio-oil partial oxidation from the 1st run with the catalyst and 5th run with the same catalyst after 4 runs of different conditions for approximately 250 min and 4 times burn-out. Catalyst activity for the water-gas shift reaction was reduced as shown by the CO yield increase by 2% and CO2 yield decrease by 7%. In addition, catalyst activity for steam gasification was also decreased since the hydrogen yield as CH4 was increased by 5%. Due to the deactivation in the water-gas shift and steam gasification reaction, total atomic hydrogen yield was reduced by 37%. This deactivation may be caused by accumulation of melted ash (metal oxides) from bio-oil or slurry, which is shown below in SEM images. This shows de-activation can be a critical issue for a process. Further study should be undertaken which focuses on new types of catalysts which can maintain activity for longer times, or on gasification or burn-out conditions which do not lead to de-activation. Catalyst was subject to attrition by fluidization. Approximately 3% of catalyst was lost by attrition per 1 hour of gasification run, whereas less than 1% of sand was lost per 1 hour of gasification. Since the catalyst is a major design restriction due to its cost, this significant attrition loss should be reduced. Magrini-Bair et al. (2002) have developed a fluidizable catalyst for steam gasification of bio-oil, for which attrition was suppressed from 28.7 wt%/day (C11-NK, Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 73 commercial catalyst) to 0.5 wt%/day (their original catalyst) with similar gasification conditions to this study. Figure 3.9 Catalyst deactivation after 250 min of bio-oil partial oxidation (conparison of 1st run and 5th run on the same catalyst bed at =0.5 and ~845°C) 3.3.6 Surface changes after the bio-oil and the slurry gasification The surface of the catalyst and the sand are of importance in terms of activity, as blocking the surface by ash or carbon deposits may cause active surface area decrease and catalyst deactivation. Figure 3.9 shows SEM images of unused fresh catalyst and sand. The surface of the catalyst was highly porous, while the surface of the sand was very smooth with very little pore structures. The subsequent SEM images (Figure 3.10 and 3.11) were taken after 0 20 40 60 80 100 842°C 847°C C ar b o n y ie ld (% ) CO CO2 CH4 C2-C4 1st run 5th run 0 50 100 150 200 842°C 847°C H y d ro g en y ie ld [ at o m ic m o l % ] H2 CH4 C2-C4 1st run 5th run Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 74 gasification of the bio-oil and/or the slurry gasification and partial oxidation runs. Figure 3.10 shows the surfaces of the catalyst after gasification of: a) the bio-oil; and b) the slurry. The surface became smoother than that of the fresh catalyst, probably due to ash derived by the bio- oil or the slurry. However, highly porous surfaces were also found in places. It is suspected that the attrition of the catalyst may have created the appearance of porous surfaces. The BET surface areas (N2, 77K) of unused and used catalysts for bio-oil and slurry gasifications were measured as: 6.7, 5.6 and 5.3 m 2 /g, respectively. The catalyst surface area decreased through the gasification operations. In addition, needle-shaped crystals were found in places from both the catalyst after the bio-oil and slurry gasification. Those crystals are probably metal oxides derived from the ash contents contained in bio-oil and bio-oil/char slurry. Metal analysis of the used catalysts was conducted (Table 3.7), however, it did not reveal the composition of the crystals due to their rather limited amounts. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 75 Table 3.7. Metal analysis of the catalyst (RK-212) and the sand after gasification (*analyzed by icp after digestion by aqua regia) Unused Catalyst Used catalyst, Bio-oil Used catalyst, Slurry Unused sand Used sand, Bio- oil Used sand, Slurry Unit Al 32.22 32.32 31.77 0.28 0.28 0.30 wt% Ca 2.40 2.40 2.44 0.03 0.02 0.09 Fe 0.10 0.10 0.10 0.11 0.11 0.12 K 1.10 0.83 0.78 0.14 0.15 0.23 Mg 8.38 8.32 8.20 0.01 0.01 0.02 Na 0.67 0.60 0.81 0.04 0.02 0.03 Ti <0.01 <0.01 <0.01 0.03 0.03 0.03 As 43 1 30 <1 <1 <1 ppm(wt) B 3187 2895 3432 24 14 28 Ba 486 386 606 167 126 143 Bi 1 5 2 2 <1 <1 Cr 8 75 67 2 6 32 Cu <1 <1 <1 2 3 9 La 1 1 2 8 5 6 Mn 2 8 9 17 25 41 Mo 5 16 16 <1 6 3 Ni 140200 139600 145000 41 33 36 Pb 224 44 33 4 3 3 Sr 8 6 11 14 13 16 Th 2 <1 <1 2 <1 <1 V 4 4 4 4 3 3 W <1 <1 <1 4 <1 1 Zn 108 3 6 4 3 8 *Ag, Au, Cd, Co, P, Sb and U contents were under detection limit. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 76 Figure 3.11 shows SEM images of the sand surface after the gasification of: a) bio-oil; and b) slurry. After the slurry gasification, the surface seemed to be coated by melted ash components, whereas the surface after the bio-oil gasification was smooth, close to the fresh surface. Since the char in the slurry has a higher ash content than the bio-oil, it is suspected that the ash coats the surface of the bed material. This may happen on the catalyst surface leading to catalyst deactivation. However, the catalyst surface did not seem to be coated as much (Figure 3.10). Since the catalyst in the present study was not designed for fluidized bed reactors, the catalyst was subjected to attrition, which could keep the catalyst surface fresh, even in the presence of higher ash content. However, attrition leads to significant catalyst loss; it cannot be counted as a benefit for catalyst improvement. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 77 Figure 3.10 a) SEM images of a) fresh catalyst; and b) fresh sand Figure 3.11 SEM images of catalyst surface after a) bio-oil gasification; and b) slurry gasification Figure 3.12 SEM images of sand surface after a) bio-oil gasification; and b) slurry gasification 20 m 20 m 20 m 20 m 20 m 20 m a) b) b) a) b) a) Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 78 3.4 Conclusions Steam gasification of bio-oil and bio-oil/char slurry was conducted using a lab-scale fluidized bed reactor. The effect on the product gas yield of catalysis was studied, as well as the gasification temperature and feedstock effects under catalytic steam gasification; and the space velocity and the steam to carbon ratio effects under non-catalytic steam gasification. Catalysis of the water-gas shift reaction and steam gasification, significantly affected the product gas yields: larger H2 yield and smaller CO and hydrocarbons yields. In addition, the carbon conversion to gas was higher under the catalytic steam gasification than for non-catalytic steam gasification. In addition, catalyst appeared to suppress generation of residual carbon during steam gasification, more effectively at higher temperature range of 755–815°C. Therefore, catalysis is necessary to yield the maximum amount of H2, while high temperature is needed for high carbon conversion to gas. With increasing gasification temperature, CO and CO2 yield increased for non-catalytic steam gasification. However, the gasification temperature did not show any clear effect on CO and CO2 yield under the catalytic conditions. For both catalytic and non-catalytic steam gasification: 1) the carbon conversion to gas from the slurry steam gasification was lower than that from bio-oil, probably due to the initial char content; and 2) the hydrocarbon yield was not affected clearly by the gasification temperature. Limited effects of the space velocity and the steam-to-carbon ratio were shown under the non-catalytic steam gasification in the range of experimental setting in the present study. Since the carbon conversion is less than 100%, i.e., much lower in slurry steam gasification, the residual unconverted carbon must be removed from the bed to prevent accumulation. Using a dual-bed gasifier could reduce the external energy input to supply heat for the steam gasification reaction. The H2 and CO yields obtained under the Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 79 catalytic steam gasification of both the bio-oil and slurry were close to the values predicted by the equilibrium model, in which the kinetic effects (existence of the unconverted carbon and hydrocarbons) were taken into account. Gas yield results appeared consistent with those from the literature. The product gas yield can be calculated reasonably using the parameters for the model determined empirically in the present study. Catalyst was subject to deactivation which caused decreases in CO and H2 yields, and increases in CO2 and CH4 yields. The surfaces of the catalyst and the sand seemed to be coated by ash contents after the slurry gasification due to the slurry’s larger amount of ash content than bio-oil. Attrition of the catalyst was measureable in gasification runs of one-hour duration. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 80 3.5 References Bridgwater, A. V., Czernik, S. and Piskorz, J. (2001) An overview of fast pyrolysis, in: Bridgwater, A. V. (Ed.), Progress in Thermochemical Biomass Conversion, Blackwell Science, Oxford, vol.2, pp. 977-997. Czernik, S., Evans, R. and French, R. (2007) Hydrogen from biomass-production by steam reforming of biomass pyrolysis oil. Catalysis Today 129, 265-268. Dinjus, E., Henrich, E. and Weirich, F. (2004) A two stage process for synfuel from biomass. in: IEA bioenergy agreement task 33: Thermal gasification of biomass, task meeting, Vienna, May 3–5. Henrich, E. (2005) Clean syngas from biomass pressurized entrained flow gasification of slurries from fast pyrolysis. in: SYNBIOS - Second generation automotive biofuel conference, Stockholm, Sweden, May 18–20. Henrich, E., Dahmen, N. and Dinjus, E. (2009) Cost estimate for biosynfuel production via biosyncrude gasification. Biofuels, Bioproducts and Biorefining 3, 28-41. Li, X., Grace, J. R., Watkinson, A. P., Lim, C. J. and Ergudenler, A. (2001) Equilibrium modeling of gasification: a free energy minimization approach and its application to a circulating fluidized bed coal gasifier. Fuel 80, 195-207. Li, X., Grace, J. R., Lim, C. J., Watkinson, A. P., Chen, H. P. and Kim, J. R. (2004) Biomass gasification in a circulating fluidized bed. Biomass and Bioenergy 26, 171-193. Magrini-Bair, K. et al. (2002) Fluidizable catalysts for producing hydrogen by steam reforming biomass pyrolysis liquids. in the 2002 U.S. DOE Hydrogen Program Review (National Renewable Energy Laboratory, Golden, Colorado. Marda, J. R., DiBenedetto, J., McKibben, S., Evans, R. J., Czernik, S., French, R. J. and Dean, A. M. (2009) Non-catalytic partial oxidation of bio-oil to synthesis gas for distributed hydrogen production. International Journal of Hydrogen Energy 34, 8519-8534. Massey, L. G. (1979) Coal gasification for high and low Btu fuels, in Coal Conversion Technology, Wen C. Y. and Lee, E. S., eds., Addison-Wesley, Reading, Massachussett, pp. 313-427. Pfeifer, C., Puchner, B. and Hofbauer, H. (2009) Comparison of dual fluidized bed steam gasification of biomass with and without selective transport of CO2. Chemical Engineering Science 64, 5073-5083. Chapter 3. Steam Gasification of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 81 van Rossum, G., Kersten, S. R. A. and van Swaaij, W. P. M. (2007) Catalytic and noncatalytic gasification of pyrolysis oil. Industrial & Engineering Chemistry Research 46, 3959-3967. Sakaguchi, M., Watkinson, A. P. and Ellis, N. Partial oxidation of bio-oil and bio-oil/char slurry in a fluidized bed reactor. to be submitted Sakaguchi, M. Watkinson, A. P. and Ellis, N. Steam gasification reactivity of char from rapid pyrolysis of bio-oil/char slurry. to be submitted 82 CHAPTER 4 Partial Oxidation of Bio-Oil and Bio-Oil/Char Slurry in a Fluidized Bed Reactor 3 4.1 Introduction Increased interest in renewable resources from concerns about climate change caused by anthropogenic greenhouse gas, mainly CO2 (IPCC, 2007), and demand for a secure supply of fuel, energy and chemicals have increased the interest in biomass as a renewable and sustainable resource candidate. Biomass-derived fuels or chemicals obtained from short rotation forestry and other energy crops can contribute to reducing net CO2 emissions. Biomass can be converted to transportation fuels and chemicals by thermochemical or biological processes. Synthesis gas production is a key first step in the thermochemical route for producing synthesized fuels and/or materials. Either solid primary biomass or secondary products derived from pyrolysis processes may be converted to gas by gasification technology. In fast pyrolysis processes, biomass is heated up to around 500°C in absence of oxygen within a few seconds and decomposed to gas, vapour and char. The condensed liquid product from the vapour, bio-oil is a dark brown-coloured liquid of similar elemental composition to the feedstock biomass material (Bridgwater et al., 2001). Due to its high density (typically 1200 kg/m 3 ) and its liquid form bio-oil can be readily stored, and pumped, leading to reduced storage and transportation cost compared to dry biomass. When mixed with the by-product char from the same process, a bio-oil/char slurry of density 1300 kg/m 3 can be prepared (at 80 wt% bio-oil/20 3 A version of this chapter will be submitted for publication. Sakaguchi, M., Watkinson, A. P. and Ellis, N. Partial oxidation of bio-oil and bio-oil/char slurry in a fluidized bed reactor. Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 83 wt% char). The slurry has an energy density 32% higher than the original biomass fed to the pyrolyzer. Partial oxidation of the bio-oil or slurry with air produces a gas useful for fuel. With pure oxygen a synthesis gas is produced which can be converted to high-quality fuels and chemicals. As carbon content of the fuel controls the maximum yields of H2 and CO which are important factors for the yields of synthetic liquid products, slurry of high carbon content is an attractive feedstock for synthesis gas production. van Rossum et al., (2007) studied bio-oil partial oxidation in a catalytic and non-catalytic fluidized bed reactor, and investigated the catalytic effect on syngas yield, hydrocarbon yield and carbon-to-gas conversion. Marda et al., (2009) studied non-catalytic partial oxidation of bio-oil in which bio-oil was atomized and gasified directly in an O2/He atmosphere without a bed over a wide range of temperatures (625–850°C), and showed that the ratio of air to feedstock affected the conversion to gas more than temperature. Partial oxidation of bio-oil/char slurry is limited to studies of oxygen blown, pressurized, entrained-flow gasification at 1200-1600°C, to produce synthesis gas (Dinjus et al., 2004; Henrich, 2005). In the present study, the slurry and bio-oil were gasified by partial oxidation in a fluidized bed reactor at lower temperatures than in previous studies. Product gases from partial oxidation of the slurry and the bio-oil, in both catalytic and non-catalytic processes, and at varied air ratios and temperatures, were analyzed to determine the effect of gasification conditions. 4.2 Experimental details Bio-oil and char, produced from wood in a commercial-scale fast pyrolysis plant, were provided by Dynamotive Energy Systems Corporation of Canada. Char was the by-product of Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 84 the bio-oil production, in which it is separated from hot pyrolyzed gas by a cyclone. Bio-oil and char were produced from the same feedstock at the same plant at yields of 60–75 wt%, and 15– 20 wt%, respectively, with non-condensable gases (10-20 wt%). Proximate analysis of the char and the ultimate analysis of the char and bio-oil are shown in Tables 4.1 and 4.2, respectively. Water content of the bio-oil was 25.2 wt%. Bio-oil/char slurry was prepared by mixing 80 wt% bio-oil and 20 wt% char. Prior to mixing, char was crushed and sieved to a particle size below 38 m. Particle size of the char was 5.9 m (median), measured using the Mastersizer 2000 (Malvern Instruments). Table 4.1 Proximate analysis of Original Char in wt% Moisture Volatile Matter (dry basis) Fixed Carbon (dry basis) Ash (dry basis) 2.3 27.1 67.1 5.8 Table 4.2 Ultimate analyses of bio-oil and Original Char in wt%; bio-oil is shown in the wet basis and char is shown in the dry ash free basis. Sample C H N S O (by diff.) Bio-oil 42.5 7.2 >0.3 >0.3 49.7 Char 76.5 3.7 >0.3 >0.3 19.2 *Ultimate analysis of bio-oils was done by Canadian Microanalytical Service Ltd., Delta, British Columbia 4.2.1 Fluidized bed material A commercial naphtha steam-reforming catalyst, RK-212 (composed of 12–15% Ni, 0– 3% NiO, 25–30% MgO, 1–2% K2O, 1–4% CaO and 60–65% Al2O3), from Haldor-Topsoe was used as bed material for catalytic partial oxidation. To understand better the catalytic effect, sand Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 85 was also used as a bed material for non-catalytic partial oxidation. Both catalyst and sand were crushed and sieved into the particle size between 180 and 355 m. 4.2.2 Gasification setup Partial oxidation experiments were carried out using a lab-scale fluidized bed reactor (Figure 4.1). The reactor was made of 310 stainless steel, and comprised of 3-inch diameter (nominal) pipe (I.D.=77.9 mm, h≈800 mm) with a distribution plate. It was surrounded by a 9 kW furnace. The reactor was charged with 0.6 L (bulk) of either the catalyst or the sand. The bed was fluidized by superheated steam, and air when partial oxidation was carried out. The bio-oil and slurry were fed from the side of the fluidized bed through an atomizer nozzle which is fully surrounded by a cooling jacket to keep the feedstock temperature below 80°C to avoid plugging by thermal decomposition. Excess steam in the product gas was condensed and separated by a condenser. Fine char and catalyst particles which were possibly generated in the reactor were captured by an internal cyclone in the reactor, and a filter after the condenser. Product gas flow was measured by a volumetric flow meter combined with a thermocouple and a pressure transducer with which the product mass flow rate was determined. The concentrations of H2, N2, CO, CO2 and CH4 were measured by micro gas chromatograph CP-4900 (Varian, Inc.) with COX column and thermal conductivity detector, and C2–C4 components (acetylene, ethylene, ethane, propene, propane, iso-butane, 1-butene and butane) were measured by gas chromatograph/mass spectroscopy, GC-3800/MS-4000 (Varian, Inc.) with a capillary column, CP-PoraBOND Q fused silica, 25 m × 0.25 mm. Temperatures and product gas flow rates were recorded during experiments. Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 86 Figure 4.1 Schematic of fluidized bed partial oxidation experimental apparatus 4.2.3 Experimental procedure When the catalyst was used as a bed material, H2/N2 (~50% H2, from 400°C for approximately 2 hours) was introduced from the bottom of the reactor for activation. To atomize the bio-oil and the slurry, a mixture of air and pure N2, were injected as atomizing gases. When the sand was the bed material, the reactor was heated up to the gasification temperature with air injection. The bio-oil and the slurry were fed at 7.5 g/min and 6.6 g/min, respectively, and water was introduced to a steam generator at the feeding rates of 8.7 g/min and 8.2 g/min for bio-oil Condenser Fluidized bed reactor Condensate collector Steam generator Cooling jacket + Atomizer Micro-GC Filter Flow meter After burner To Vent Air Pump Rotameters N2 Pump Sampling for GC/MS Bio-oil Slurry H2O H2 Air N2 Rotameters Ice trap To Vent Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 87 and slurry partial oxidation, respectively. Air was introduced from the bottom of the reactor to provide an air ratio of =0.1–0.5. (=1 corresponds to complete combustion of feedstock) Typically the ratio of air used in atomization to that used for fluidization was 3 to 9. After each gasification experiment, methanol was introduced to the atomizer to clean the nozzle, and then an air/N2 mixture was introduced to remove carbon residue in the reactor which could possibly accumulate during the experiment. 4.2.4 Definitions In the present study, the hydrogen and carbon yields are described in mole% of elemental hydrogen and carbon in each component of the product gas produced from the feedstock without inherent water: 1) H2, CH4 and C2–C4 components shown above for the hydrogen yield; and 2) CO, CO2, CH4 and C2–C4 components for the carbon yield. The carbon conversion to gas is the sum of the carbon yield of each product gas component. The hydrogen yield larger than 100% can be possible due to steam gasification reaction in which water reacts with the feedstock yielding H2 and CO followed by the water-gas shift reaction, CO + H2O ⇄ H2 + CO2 (4.1) which consumes CO yielding more H2. The air ratio () is the fraction of oxygen introduced into the reactor compared to that required for complete combustion; =1 means that sufficient oxygen is supplied to yield carbon dioxide and water as described below, C𝑥H𝑦O𝑧 + 𝑥 + 𝑦 4 − 𝑧 2 O2 → 𝑥CO2 + 𝑦 2 H2O (4.2) Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 88 where CxHyOz represents the chemical formula of bio-oil or bio-oil/char slurry. For bio-oil, =1 corresponds to 4.1 L air/g bio-oil. The steam to carbon ratio (H2O/C) is the molar ratio of the steam plus the inherent water of the feedstock introduced to the reactor and the carbon in the feedstock. The gas hourly space velocity, GC1HSV is defined as the volume of methane, assuming 100% of carbon in the feedstock is converted to methane, at standard temperature and pressure per unit bulk volume of catalyst per hour. 4.3 Results and discussion Table 4.3 shows a typical product gas composition and heating value from partial oxidation of bio-oil and bio-oil/char slurry. The nitrogen concentration was 50–70% which was from atomizing the feedstock, and the steam concentration was c.a. 40%. The air ratio was set at values of 0.1, 0.3 and 0.5 for catalytic and non-catalytic partial oxidation. The temperature was in the range of 790–850°C. H2O/C was set at 2.1 where H2/CO mole ratio was estimated as 2 at equilibrium, optimum for Fischer-Tropsch synthesis and/or methanol synthesis. The GC1HSV was set at 510–600 h-1. Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 89 Table 4.3 Product gas composition (in mol%) and heating value from partial oxidation of the bio-oil and the slurry with the catalyst and the sand at T≈842–848°C, H2O/C≈2.1, =0.5 and GC1HSV≈550–590 h -1 ; wet with nitrogen and dry nitrogen free basis Bed material Feed (Run name) Basis H2 CO CO2 CH4 C2+ N2 H2O* HHV- MJ/m 3 Sand Bio-oil (POSE09-1) Wet, N2 included 5.3 6.7 7.9 1.0 0.2 35.0 41 3.2 Dry, N2 free 22 28 33 4.3 0.7 - - 7.8 Slurry (POSE15-1) Wet, N2 included 3.7 4.0 8.8 0.8 0.2 38.6 43 2.3 Dry, N2 free 21 22 49 4.3 0.9 - - 7.2 Catalyst Bio-oil (POAU31-1) Wet, N2 included 15.7 3.3 12.8 0 0 34.4 32 3.3 Dry, N2 free 46 9.8 38 0 0 - - 6.7 Slurry (POOC08-1) Wet, N2 included 9.4 1.9 11.8 0.2 0 35.9 39 2.4 Dry, N2 free 38 7.8 47 0.9 0 - - 5.7 *H2O concentration was calculated by H elemental balance. Due to measurement errors and undetectable components of the micro-GC (i.e., water), the total concentration is < 100%. 4.3.1 Effect of air ratio The hydrogen and carbon yields at different air ratios in the catalytic and the non- catalytic partial oxidation are shown in Figure 4.2 (catalytic) and Figure 4.3 (non-catalytic). With increasing air ratio, the CO2 yield increased and the H2 yield decreased. This was caused by increased amounts of oxygen which reacted with chemical species containing carbon and hydrogen yielding CO2 and H2O. As a large amount of air reduces the quality of the produced gas, a low air ratio is preferred for stronger fuel gas production. In the present apparatus, the furnace provides heat to permit operation at lower air ratios than would be otherwise possible. There were no clear tendencies in the air ratio effect (0.1 < λ < 0.5) on the carbon conversion. This is probably because oxygen in the system firstly reacts with gaseous species in the reactor (such as H2 and CO), and residual carbon remains unconverted due to its low reactivity, unless Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 90 excess amount of oxygen is supplied. For continuous autothermal operation, this carbon residue should be removed either in a dual-bed gasifier, or by chemical looping combustion in which the carbon residue is transported to a separate combustion process with the bed material to be burnt and recycled back to the partial oxidation reactor. The heat of combustion of the carbon residue can thus be transported by the enthalpy of the bed material. This helps supply heat for the endothermic reactions required for the steam gasification reaction, especially at low air-ratio conditions. Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 91 Figure 4.2 a) Carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) on the dry feed stock basis at catalytic partial oxidation, H2O/C=2.1, GC1HSV=510–600 h -1 Figure 4.3 a) Carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) on the dry feed stock basis at non-catalytic partial oxidation, H2O/C=2.1, GC1HSV=510– 600 h -1 0 20 40 60 80 100 Bio-oil Slurry Bio-oil Slurry Bio-oil Slurry C a rb o n y ie ld [ a to m ic m o l % ] =0.09 =0.11 =0.34=0.29 =0.47 =0.51 CO CO2 CH4 C2-C4 790°C 818°C 848°C802°C 842°C 850°C 0 50 100 150 200 250 300 Bio-oil Slurry Bio-oil Slurry Bio-oil Slurry H y d ro g e n y ie ld [ a to m ic m o l % ] H2 CH4 C2-C4 =0.09 =0.11 =0.34=0.29 =0.47 =0.51 790°C 818°C 848°C802°C 842°C 850°C 0 20 40 60 80 100 Bio-oil Slurry Bio-oil Slurry Bio-oil Slurry C a rb o n y ie ld [ a to m ic m o l % ] CO CO2 CH4 C2-C4 =0.10 =0.11 =0.29=0.36 =0.48 =0.53 790°C 814°C 839°C843°C 844°C 847°C 0 50 100 150 200 250 Bio-oil Slurry Bio-oil Slurry Bio-oil Slurry H y d ro g e n y ie ld [ a to m ic m o l % ] H2 CH4 C2-C4 =0.10 =0.11 =0.29=0.36 =0.48 =0.53 790°C 814°C 839°C843°C 844°C 847°C a b a b Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 92 4.3.2 Effect of temperature Figures 4.4 and 4.5 show the carbon and hydrogen yield at different partial oxidation temperatures. At the same air ratio, the H2 yield was larger at higher temperature than at lower temperature under both catalytic and non-catalytic conditions. The total hydrogen yield (except for H2O) showed a similar tendency. In addition, decrease of the CO yield at higher temperature corresponded to the increase of H2 in the catalytic conditions, while this did not happen under non-catalytic conditions. This indicates that the catalysis of the water-gas shift reaction, which produces H2 and CO2 from CO and H2O, increased the H2 yield significantly, while CO was not well converted to H2 and CO2 by the water-gas shift reaction without catalysis. The carbon and hydrogen yields as hydrocarbons including CH4 decreased at higher temperature under both catalytic and non-catalytic conditions. This indicates that hydrocarbons were decomposed and steam gasified yielding H2 and CO to greater extents at higher temperature. Meanwhile, no clear tendencies were found in the effect of temperature on the total carbon conversion. Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 93 Figure 4.4 The effect of temperature on: a) the carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) the hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) ; with non-catalytic partial oxidation, H2O/C=2.1, GC1HSV=510–600 h -1 ; BO: bio-oil, SL: slurry 0 20 40 60 80 100 843 °C 744 °C 839 °C 744 °C 844 °C 745 °C 847 °C 744 °C BO BO SL SL BO BO SL SL C a rb o n y ie ld [ a to m ic m o l % ] CO CO2 CH4 C2-C4 =0.29 =0.29 =0.40=0.36 =0.48 =0.54=0.47 =0.53 0 50 100 150 200 250 843 °C 744 °C 839 °C 744 °C 844 °C 745 °C 847 °C 744 °C BO BO SL SL BO BO SL SL H y d ro g e n y ie ld [ a to m ic m o l % ] H2 CH4 C2-C4 =0.29 =0.29 =0.40=0.36 =0.48 =0.54=0.47 =0.53 a b Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 94 Figure 4.5 The effect of temperature on: a) the carbon yield (mol% - atomic) as CO, CO2, CH4 and hydrocarbons (C2-C4); and b) the hydrogen yield (mol% - atomic) as H2, CH4 and hydrocarbons (C2-C4) with catalytic partial oxidation, H2O/C=2.1, GC1HSV=510–600 h -1 ; BO: bio-oil, SL: slurry 0 20 40 60 80 100 802 °C 758 °C 848 °C 748 °C 842 °C 746 °C 850 °C 749 °C BO BO SL SL BO BO SL SL C a rb o n y ie ld [ a to m ic m o l % ] CO CO2 CH4 C2-C4 =0.29 =0.32 =0.34=0.34 =0.47 =0.51=0.52 =0.51 0 50 100 150 200 250 802 °C 758 °C 848 °C 748 °C 842 °C 746 °C 850 °C 749 °C BO BO SL SL BO BO SL SL H y d ro g e n y ie ld [ a to m ic m o l % ] H2 CH4 C2-C4 =0.29 =0.32 =0.34=0.34 =0.47 =0.51=0.52 =0.51 a b Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 95 4.3.3 Difference between bio-oil and slurry in the product gas yield At the same air ratio, partial oxidation of the slurry yielded less CO and H2 than that of bio-oil except for =0.1 in non-catalytic condition. As the slurry contains char which is close to solid carbon, initial amounts of vaporized or gasified components in the reactor should be limited, and less than for bio-oil. This would cause less carbon conversion, and lower CO and H2 yields in the slurry partial oxidation. In both catalytic and non-catalytic conditions, the carbon conversion of the slurry to gas was less than for bio-oil. The catalyst did not indicate a clear improvement on the carbon conversion in the partial oxidation. The exception at =0.1 in non- catalytic condition can be caused by the relatively large temperature difference, i.e., the bio-oil was gasified at lower temperature than the slurry, reducing the H2 yield. 4.3.4 Effect of catalysis At the same temperature, air ratio and feedstock, the carbon conversion to gas from the catalytic and the non-catalytic conditions were similar, except for the =0.1 case, where the carbon conversion of the bio-oil catalytic partial oxidation was lower than for the slurry, and the difference was relatively large. A significant difference was observed in the hydrogen yield and the ratio of yields of CO to CO2. By catalysis of the water-gas shift reaction, CO reacts well with H2O yielding CO2 and H2, while CO remains unreacted and the hydrogen yield was low under non-catalytic conditions. In addition, the yield of hydrocarbons under catalytic conditions was also significantly reduced by catalysis of the steam reforming reactions. Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 96 4.3.5 Comparison with thermodynamic equilibrium The data were compared with values calculated assuming thermodynamic equilibrium. To predict the product gas composition, the modeling approach for gasification of carbonaceous materials by Li et al. (Li et al., 2001) was applied. In the model, the system which included C, H, O, N and S, was simplified to 42 gaseous species and two solid species. The model was solved by minimizing Gibbs free energy of the system using the RAND algorithm. Details of the methodology are provided in the literature (Li et al., 2001). 4.3.5.1 H2 and CO yields Figure 4.6 compares the H2 and CO yields between obtained data and the model- predicted values at each experimental condition. The H2 yield was close to equilibrium and the difference was small at different air ratios; while the non-catalytic partial oxidation yielded much less H2 than equilibrium, and the difference from the equilibrium became larger with increasing air ratio. The CO yield was greater under non-catalytic conditions and less under catalytic conditions due to the catalysis of the water-gas shift, yielding H2 and consuming CO. Increase of air ratio without catalysis did not result in a product gas composition being closer to equilibrium. Especially when H2O is fed to increase H2 yield, catalysis is necessary to achieve the expected product yield. Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 97 Figure 4.6 a) Hydrogen yield as H2, and b) carbon yield as CO compared with modified equilibrium model ; 790–850°C, H2O/C=2.1, GC1HSV=510–600 h -1 , ●: bio-oil – catalytic, ■: slurry – catalytic, ○: bio-oil – non-catalytic, □: slurry – non-catalytic 4.3.5.2 H2/CO ratio Figure 4.7 shows experimental H2/CO molar ratios compared to values predicted from the model at each experimental condition. Despite the experimental conditions set in order to yield the product gas H2/CO ratio around 2, the results for all conditions deviated from this ratio; i.e., the results from the catalytic and the non-catalytic conditions were significantly higher and lower, respectively, than the expected ratio. Under actual experimental conditions, the carbon conversion was 66–96% which indicates a smaller amount of carbon involved in actual reaction, and this caused reaction at a higher H2O/C ratio than expected, while the carbon conversion was 100% for all the conditions in the equilibrium model. Therefore, the equilibrium shifted to the right in Equation 4.1 due to the excess amount of H2O involved in the reaction. This resulted in high H2/CO ratios under catalytic conditions which exceeded equilibrium. 0 100 200 300 0 100 200 300 H y d ro g en y ie ld a s H 2 (% ) Hydrogen yield as H2, equilibrium model (%) 0 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70 C ar b o n y ie ld a s C O ( % ) Carbon yield as CO, equilibrium model (%) a b Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 98 Figure 4.7 H2/CO ratio compared with modified equilibrium model; 790–850°C, H2O/C=2.1, GC1HSV=510–600 h -1 , ●: bio-oil – catalytic, ■: slurry – catalytic, ○: bio-oil – non-catalytic, □: slurry – non-catalytic 0 1 2 3 4 5 6 0 1 2 3 4 5 6 H 2 /C O r a ti o ( m o l/ m o l) H2/CO ratio, equilibrium model (mol/mol) Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 99 4.3.5.3 Modified model To better estimate the product gas composition, elemental abundances in the partial oxidation system should be adjusted, as done by Li et al. (2004), i.e., taking kinetic effects, such as unconverted carbon and hydrocarbons, which influence real processes by kinetics and/or mass transfer, into account. In the modified model, unconverted carbon, and carbon and hydrogen in hydrocarbons in the product gas were initially withdrawn from elemental abundances for the equilibrium calculation. The hydrocarbons were subsequently added to the result of the equilibrium calculation. Figures 4.8 and 4.9 show H2 and CO yields, and H2/CO ratio, respectively, between our data and the values from the modified model at each experimental condition. Under catalytic conditions, the H2 and CO yields were very close to equilibrium for both the slurry and the bio-oil, while with non-catalytic conditions the H2 yield was much less than at equilibrium, and the CO yield was much higher than at equilibrium. As a result, the H2/CO ratios under catalytic conditions were close to the values estimated by the modified model, while under non-catalytic conditions, the ratio was much less. In addition, the estimated H2/CO ratio shifted higher than the original setting due to the change in elemental abundance of carbon and hydrogen. Therefore, especially in catalytic partial oxidation, the product gas yields are reasonably predictable once the parameters for the kinetic modified model, carbon conversion and hydrocarbon yield, are determined empirically from the actual gasification system. Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 100 Figure 4.8 a) Hydrogen yield as H2, and b) carbon yield as CO compared with modified equilibrium model; 790–850°C, H2O/C=2.1, GC1HSV=510–600 h -1 , ●: bio-oil – catalytic, ■: slurry – catalytic, ○: bio-oil – non-catalytic, □: slurry – non-catalytic Figure 4.9 H2/CO ratio compared with modified equilibrium model; 790–850°C, H2O/C=2.1, GC1HSV=510–600 h -1 , ●: bio-oil – catalytic, ■: slurry – catalytic, ○: bio-oil – non-catalytic, □: slurry – non-catalytic 0 100 200 300 0 100 200 300 H y d ro g en y ie ld a s H 2 (% ) Hydrogen yield as H2, modified equilibrium model (%) 0 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70 C ar b o n y ie ld a s C O ( % ) Carbon yield as CO, modified equilibrium model (%) 0 1 2 3 4 5 6 0 1 2 3 4 5 6 H 2 /C O r a ti o ( m o l/ m o l) H2/CO ratio, modified equilibrium model (mol/mol) Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 101 4.4 Conclusions The effect of air ratio, temperature and catalysis on partial oxidation of bio-oil and bio- oil/char slurry was studied. Catalysis of the water-gas shift reaction and the steam gasification significantly affected the product gas yield, resulting in large H2 yields and small CO and hydrocarbons yields. At higher temperatures, the H2 yield increased and the hydrocarbon yield was decreased, due to successful decomposition of hydrocarbons. The air ratio controlled total synthesis gas yield (H2 and CO) as increased air consumed synthesis gas species via combustion, yielding CO2 and H2O. Bio-oil carbon conversion to gas was greater than for slurry due to its absence of initial char content. The H2 yield from the catalytic partial oxidation was close to that at equilibrium, while the non-catalytic partial oxidation yielded much less H2. The H2/CO ratio of the product gas greatly exceeded the equilibrium model prediction in catalytic partial oxidation, due to the carbon conversion being less than 100%. This reduced actual carbon elemental abundance, involved in the reaction system, caused greater effective H2O/C ratios. As it shifted the equilibrium, consuming CO to yield additional H2 with the help of the catalysis, the H2/CO ratio increased. Using a kinetically-modified equilibrium model in which unconverted carbon and hydrocarbons were excluded, the product gas yield can be estimated reasonably for the catalytic partial oxidation, as catalysis makes the reaction system close to equilibrium. Once the parameters for the modified model, the carbon conversion to gas and the hydrocarbon yield, are determined empirically for real processes, reasonable prediction of product gas yield would be available. For continuous autothermal operation with either bio-oil or slurry, unconverted carbon should be removed from the gasification stage, and combusted separately in a dual- gasifier or chemical looping combustion mode. Chapter 4. Partial Oxidation of Bio-oil and Bio-oil/Char Slurry in a Fluidized Bed Reactor 102 4.5 References Bridgwater, A. V., Czernik, S., and Piskorz, J. (2001) An overview of fast pyrolysis. in: Bridgwater, A. V., (Ed.), Progress in Thermochemical Biomass Conversion, Blackwell Science, Oxford, vol.2, pp. 977-997. Dinjus, E., Henrich, E., and Weirich, F. (2004) A two stage process for synfuel from biomass. in: IEA Bioenergy Agreement Task 33: Thermal Gasification of Biomass, task meeting, Vienna, May 3–5. Henrich, E. (2005) Clean syngas from biomass pressurized entrained flow gasification of slurries from fast pyrolysis. in: SYNBIOS - Second generation automotive biofuel conference, Stockholm, Sweden, May 18–20. Li, X., Grace, J. R., Watkinson, A. P., Lim, C. J., and Ergudenler, A. (2001) Equilibrium modeling of gasification: a free energy minimization approach and its application to a circulating fluidized bed coal gasifier. Fuel 80, 195-207. Li, X., Grace, J. R., Lim, C. J., Watkinson, A. P., Chen, H. P., and Kim, J. R. (2004) Biomass gasification in a circulating fluidized bed. Biomass and Bioenergy 26, 171-193. Marda, J. R., DiBenedetto, J., McKibben, S., Evans, R. J., Czernik, S., French, R. J., and Dean, A. M. (2009) Non-catalytic partial oxidation of bio-oil to synthesis gas for distributed hydrogen production. International Journal of Hydrogen Energy 34, 8519-8534. van Rossum, G., Kersten, S. R. A., and van Swaaij, W. P. M. (2007) Catalytic and noncatalytic gasification of pyrolysis oil. Industrial & Engineering Chemistry Research 46, 3959-3967. 103 CHAPTER 5 A Case Study of Steam Gasification in a Dual-Bed Gasifier 4 5.1 Introduction Steam gasification and partial oxidation of bio-oil/char slurry are promising means to produce synthesis gas from biomass. However, under some conditions more than 30% of carbon remained unconverted, and accumulated in the reactor due to the low steam gasification reactivity of the slurry. In a real process, unconverted carbon would be removed from the gasifier for utilization as a heat source in a separate combustor such as is used in dual-bed gasifiers (Chapters 3–4). Corella et al. (2007) reviewed biomass gasification with pure steam in dual fluidized-bed gasifiers, describing units developed from 1979 to 2007 by reseach groups from different parts of the world. A dual-bed gasifier can provide heat for endothermic reaction from a separated combustor in which unconverted carbon from the gasifier is burnt and generating heat. By using a dual-bed gasifier, the product gas can be obtained without dilution of air or CO2, From the combustor, CO2 can be obtained at high concentration, that is suitable for CO2 capture or recycle to the other processes. In the present work, steam gasification of bio- oil/char slurry with removal of unconverted carbon by a dual-bed gasifier system was examined in a mass and heat balance computation using the kinetically modified equilibrium model. 4 A version of this chapter will be submitted for publication. Sakaguchi, M., Watkinson, A. P. and Ellis, N. A case study of steam gasification in a dual-bed gasifier. Chapter 5 A case study of steam gasification in a dual-bed gasifier 104 A p p en d ix B R esea rch n o te – A ca se stu d y o f stea m g a sifica tio n in a d u a l-b ed g a sifier 5.2 Model dual-bed gasifier system Figure 5.1 shows the dual-bed gasifier system considered in the present study. The system consists of a fluidized bed gasifier for the slurry steam gasification and a combustor in which unconverted carbon transferred with bed material from the gasifier is burnt with air. If necessary, auxiliary fuel can be fed to the combustor. After going through the combustor, the hot bed material moves back to the gasifier. The assumed reactor type is circulating fluidized bed type reactor. The number of degrees of freedom of the system is 15 in a situation of: 9 species involved, excess air introduced to the combustor, and identical temperatures of flows after the condenser (see degrees of freedom analysis below). Thus, 15 specifications (constraints) are required to determine the process. Product gas composition from the gasifier was calculated using the kinetically modified equilibrium model (Li, 2004) taking unconverted carbon into account, as outlined in Chapters 3 and 4. To determine the process, the following conditions were set (parenthesized numbers are constraints, in total 15): ■ Char content in the slurry: 10, 15, 20, 25 and 30 wt%. ■ H2O/C: 3.0, 5.5 and 8.0 mol/mol. (1) ■ The slurry is fed at 1 kg/hr directly to the gasifier kept at 850°C. (2) ■ All the pressures are set to 100 kPa (absolute). (5) ■ Temperatures of inlet water, slurry and air are 25°C. (3) ■ Heat of product gas is used to preheat water (steam) by Heat Exchanger 1. ■ Temperature of product gas after Heat Exchanger 1 is 300°C to prevent tar deposition in pipeline downstream until scrubber (Murakami et al., 2007). (1) ■ Temperature of exhaust from the combustor after Heat Exchanger 2 is 150°C. (1) Chapter 5 A case study of steam gasification in a dual-bed gasifier 105 A p p en d ix B R esea rch n o te – A ca se stu d y o f stea m g a sifica tio n in a d u a l-b ed g a sifier ■ Carbon conversion to gas: carbon amount attributed to char content. (1) ■ Hydrocarbon yield = 0% (for simplification). ■ The preheated steam is heated up to 850°C by a steam heater, if the preheated steam temperature is less than 850°C (in most cases). ■ Unconverted char is transported with the circulating bed material to the combustor in which the char is burnt with air to keep the combustor temperature at 950°C. ■ Stoichiometric air ratio in the combustor is 1.5. (1) ■ The heat capacity of the bed material is assumed to be 1.0 kJ/(kg·K) (alumina). ■ Heat losses from equipment are assumed negligible. The feedstock composition used for the calculation is shown in Table 5.1. Those are the same materials used in Chapters 3–4. The Matlab program is given as Appendix J. The code can be readily modified for different assumed values from the cases calculated. The product gas composition is determined by the gasifier temperature, the slurry feed rate and composition, the carbon conversion in the steam gasification, and the steam feed rate. Since the combustor temperature, air ratio, and unconverted carbon circulation rate are specified, the bed material circulation rate is determined by the energy balance of the combustor. With the conditions shown above, these determine the process. At the condition of H2O/C=1, exhaust temperature from Heat Exchanger 2 is higher than 150°C due to much less water being preheated. The material and energy balance sheets for all the conditions are shown in Tables B.1–B.9 in Appendix B. Chapter 5 A case study of steam gasification in a dual-bed gasifier 106 A p p en d ix B R esea rch n o te – A ca se stu d y o f stea m g a sifica tio n in a d u a l-b ed g a sifier Figure 5.1 Schematic of dual-bed gasifier for bio-oil/char slurry steam gasification Table 5.1 Elemental analysis and water content of bio-oil and char in wt%, as-received. Sample C H N S O (by diff.) Water content Higher heating value (MJ/kg) Lower heating value (MJ/kg) Bio-oil 42.5 7.2 0.3 0.3 49.7 25.2 17.0 15.5 Char 76.5 3.7 0.3 0.3 19.2 2.3 28.6 27.8 Slurry (80 wt%Bio- oil/20 wt%Char) 49.3 6.5 0.3 0.3 43.6 20.6 19.3 17.9 Bio-oil/char slurry, 25°C Reactor 850°C H2O, 25°C Combustor 950°C Air, 25°C A. Heat exchanger 1 1 2 B. Heat exchanger 2 34 6 7 8 9 10 11 Exhaust, 950°C Product gas, 300°C12Exhaust, 150°C Bed solid, 950°C Carbon + Bed solid Q C. Steam heater 5 Auxiliary fuel Chapter 5 A case study of steam gasification in a dual-bed gasifier 107 A p p en d ix B R esea rch n o te – A ca se stu d y o f stea m g a sifica tio n in a d u a l-b ed g a sifier 5.3 Equilibrium model for gasifier product gas composition Product gas composition from the gasifier was determined by an equilibrium model for gasification of carbonaceous materials (Li et al., 2001). In the model, the system which included C, H, O, N and S, was simplified to 42 gaseous species and two solid species. The model was solved by minimizing Gibbs free energy of the system using the RAND algorithm. To calculate unconverted carbon amount gererated in the gasifier, elemental abundances in the steam gasification system were adjusted at the initial stage of free energy minimization, in a similar way to that of Li et al. (2004). Other material and energy balances were calculated by separate calculation sheets. 5.4 Results and discussion 5.4.1 Effect of char content in slurry Figures 5.2 and 5.3 show 1) the effect of char content in the feed slurry on the total required process energy, total recycled energy, energy required for gasifier and energy transferred from the combustor to the gasifier by circulation of the bed material; and b) the effect of char content on the bed material circulation rate and required auxiliary fuel (slurry) amount, respectively, under the condition of H2O/C=5.5. The required energy for the gasifier slightly decreases with increasing char content, while the recycled energy by circulation of the bed material increases. Total required energy (Figure 5.2) remained constant with increasing char content, while total recycled energy increased. This recycled energy increase is caused by increased char content which also increases bed material circulation rate, resulting in larger heat transfer from the combustor to the gasifier. Chapter 5 A case study of steam gasification in a dual-bed gasifier 108 A p p en d ix B R esea rch n o te – A ca se stu d y o f stea m g a sifica tio n in a d u a l-b ed g a sifier Under the conditions specified, auxiliary fuel has to be supplied to the combustor to sustain the process. The required auxiliary fuel amount increased with decreasing char content. Because slurry with high char content generates a large amount of unconverted carbon, and it is transported to combustor for energy recovery, a larger amount of energy can be recycled with high char content. This indicates that a large amount of unconverted carbon, resulting from high carbon content in the slurry in the gasifier, helps process operation by utilizing the heat of combustion of unconverted carbon. Chapter 5 A case study of steam gasification in a dual-bed gasifier 109 A p p en d ix B R esea rch n o te – A ca se stu d y o f stea m g a sifica tio n in a d u a l-b ed g a sifier Figure 5.2 Effect of char contents in slurry on energy requirements and recycles (H2O/C=5.5) Figure 5.3 Effect of char contents in slurry on bed material circulation rate and auxiliary fuel (slurry) amount (H2O/C=5.5) 0 2 4 6 8 10 12 0 10 20 30 E n er g y ( k W /k g -f ee d st o ck ) Char contents (%) Total required energy Total recycled energy Required for gasifier Circulating energy 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 0 10 20 30 40 0 10 20 30 A u x il ia ry f u el ( k g /h k g -f ee d st o k ) B ed m at er ia l ci rc u la ti o n r at e (k g /h k g -f ee d st o ck ) Char contents (%) Bed material circulation rate Auxiliary fuel Chapter 5 A case study of steam gasification in a dual-bed gasifier 110 A p p en d ix B R esea rch n o te – A ca se stu d y o f stea m g a sifica tio n in a d u a l-b ed g a sifier 5.4.2 Etffect of H2O/C Figures 5.4 and 5.5 show the effect of H2O/C on total required process energy, total recycled energy, energy required for gasifier and energy transferred from the combustor to the gasifier by circulation of the bed material, and the effect of H2O/C on the bed material circulation rate and required auxiliary fuel (slurry) amount, respectively, using 20 wt% char slurry. Note that the lowest H2O/C ratio considered here was 1.0 mol/mol which is lower than was studied experimentally. The total required energy increased steeply with increasing H2O/C because the energy requirement for steam generation increased. Recycle energy also increased, but not as much as did the total required energy. Because the product gas final temperature is 300°C to prevent tar deposition in pipeline, the large amount of latent heat of water in the product gas cannot be recovered; the more H2O/C is used, the more energy is comsumed. If tar content was eliminated by conditions in the gasifier, the product gas temperature could be lowered, leading to substantial reductions in auxiliary fuel requirements. The auxiliary fuel amount decreases significantly with decreasing H2O/C (Figure 5.5), due to less water having to be preheated. As the amount of auxiliary fuel is sensitive to H2O/C (for example, it exceeds 1 kg/h at H2O/C=4.5), therefore the H2O/C ratio should be determined carefully not to consume much energy. As the unconverted carbon amount is constant at the experimental condition (char content in slurry is constant), the bed material circulation rate is not affected. Chapter 5 A case study of steam gasification in a dual-bed gasifier 111 A p p en d ix B R esea rch n o te – A ca se stu d y o f stea m g a sifica tio n in a d u a l-b ed g a sifier Figure 5.4 Effect of H2O/C on energy requirements and recycles for 20% char in slurry Figure 5.5 Effect of H2O/C on bed material circulation rate and auxiliary fuel amount for 20% char in slurry 0 2 4 6 8 10 12 0 2 4 6 8 10 E n er g y ( k W /k g -f ee d st o ck ) H2O/C (mol/mol) Total required energy Total recycled energy Required for gasifier Circulating energy 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 0 10 20 30 0 2 4 6 8 10 A u x il ia ry f u el ( k g /h k g -f ee d st o k ) B ed m at er ia l ci rc u la ti o n r at e (k g /h k g -f ee d st o ck ) H2O/C (mol/mol) Bed material circulation rate Auxiliary fuel Chapter 5 A case study of steam gasification in a dual-bed gasifier 112 A p p en d ix B R esea rch n o te – A ca se stu d y o f stea m g a sifica tio n in a d u a l-b ed g a sifier 5.5 Conclusions A case study of steam gasification of bio-oil/char slurry in a dual-bed gasifier system is conducted. From the material and energy balances, with product gas composition determined using the kinetically modified equilibrium model, the following conclusions may be drawn: ■ The higher char content in slurry increases bed material circulation rate, and thus the heat transfer from the combustor to the gasifier for fixed air ratio in the combustor. ■ Over the range of conditions covered, auxiliary fuel is required in all cases. ■ The energy requirement is sensitve to the H2O/C ratio since the latent heat of water cannot be recovered in this study. The produced gas exit temperature of 300°C, set to prevent tar deposition, limits heat recovery and contributes significantly to auxiliary fuel requirements. Lower water fractions lead to a more efficient process design due to savings in latent heat recovery. Additional effort should be made for heat integration to improve the process including heat recovery of latent heat of water in the product gas. Chapter 5 A case study of steam gasification in a dual-bed gasifier 113 A p p en d ix B R esea rch n o te – A ca se stu d y o f stea m g a sifica tio n in a d u a l-b ed g a sifier 5.6 References Corella, J., Toledo, J. M. and Molina, G. A (2007) Review on dual fluidized-bed biomass gasifiers. Industrial & Engineering Chemistry Research 46, 6831-6839. Li, X., Grace, J. R., Watkinson, A. P., Lim, C. J. and Ergudenler, A. (2001) Equilibrium modeling of gasification: a free energy minimization approach and its application to a circulating fluidized bed coal gasifier. Fuel 80, 195-207. Li, X., Grace, J. R., Lim, C. J., Watkinson, A. P., Chen, H. P. and Kim, J. R. (2004) Biomass gasification in a circulating fluidized bed. Biomass and Bioenergy 26, 171-193. Murakami, T., Xu, G., Suda, T., Matsuzawa, Y., Tani, H. and Fujimori, T. (2007) Some process fundamentals of biomass gasification in dual fluidized bed. Fuel 86, 244-255. 114 CHAPTER 6 Conclusions and Suggestions for Further Work 6.1 Conclusions Bio-oil and bio-oil/char slurry are promising forms of biomass for transportation to centralized sites for conversion into useful products through gasification. Despite numerous works on steam gasification targeting bio-oil fractions as a feedstock, limited research is available where whole bio-oil was used, probably due to its complex polymerization and coking properties at high temperature gasification conditions. As well, gasification of bio-oil/char slurry has been limited to partial oxidation using oxygen in a high temperature and pressure process (Dinjus et al., 2004; Henrich, 2005). Therefore, in the present study, gasification of whole bio-oil and bio-oil/char slurry was investigated by both steam gasification and partial oxidation at rather lower temperature conditions. To investigate the role of char in steam gasification of bio-oil/char slurry injected into gasifiers, steam gasification reactivity of char made from rapid pyrolysis of bio-oil/char slurry was studied via thermogravimetry (Chapter 2). Secondly, gasification of straight bio-oil and bio-oil/char slurry was conducted in a lab-scale fluidized bed reactor system constructed for this work, in order to investigate actual gasification performance and produced gas properties (Chapters 3–4). Thirdly, the material and energy balance of steam gasification in a dual-bed gasifier was conducted to investigate its efficiency at various operating conditions (Chapter 5). Kinetics of gasification of char originally produced with bio-oil, and char produced by pyrolysis of bio-oil/char slurry was studied in a thermogravimetric analyzer modified to accommodate steam. The rate of reaction increased with fractional conversion between 0.2 and Chapter 6 Conclusions and suggestions for further work 115 0.8. The reactivity of Slurry Char was very close to that of Original Char in the temperature range of 900–1200°C. At 900°C, as conversion increased, the reactivity of Slurry Char became less compared to that of Original Char. This deactivation was consistent with the change in the surface area by rapid pyrolysis. Heating rate of bio-oil/char slurry injected into a steam gasification reactor is an important factor for the gasifier system design; therefore, a range of heating rates was tested. The steam partial pressure was varied over the range 10 to 50 kPa. The kinetic parameters of steam gasification of Slurry Char and Original Char according to the n-th order kinetic model were determined at X=0.5: E=235 kJ/mol, k0=1.69×10 6 and n=0.41 for char made from bio-oil/char slurry, and E=219 kJ/mol, k0=7.38×10 5 and n=0.34 for Original Char. These activation energies over 200 kJ/mol and reaction orders below 0.6 are similar to values for wood char found in the literature. Discrepancies with the values in literature are probably due to uncertainty of model fitting, or origin of chars. From the reactivity work, it is suggested that gasifiers for the slurry can be designed as for char gasification to create fine droplets for rapid heating in the gasifier in order for the resulting char to be of high reactivity. A fluidized bed suitable for the gasification of bio-oil and bio-oil/char slurry has been designed and fabricated (Appendix C). The atomizer inserted into the gasifier required careful design in order to ensure proper injection of the feed due to high viscosity and the polymerization property of the bio-oil under the high temperature environment. Using a nozzle for liquids of high viscosity with surrounding cooling jacket, stable injection was achieved. The gasification system was operated successfully at bio-oil feed rate of 0.16–0.32 kg/h for superficial gas velocities of 3Umf to 12Umf. Bed material was sand or catalyst. On a dry N2 free basis, gases contained typically 17–61% H2, and 7–40% CO. Chapter 6 Conclusions and suggestions for further work 116 In both steam gasification and partial oxidation, the presence of catalyst strongly affected both product gas composition and yield. Specifically, the H2/CO ratio was significantly higher in catalytic gasification (~4) than in non-catalytic gasification (~1) due to catalysis of the steam gasification and water-gas shift reactions. This resulted in approximately two times higher H2 yields and half CO yields in catalytic gasification. Carbon conversion to gas was greater with bio-oil than bio-oil/char slurry due to the absence of char. In partial oxidation, the air ratio affected H2 and CO yield significantly: large air ratios reduced the H2 and CO yield and increased CO2 yield because the increased amount of oxygen oxidized more of those components. In steam gasification, the carbon conversion of the slurry to gas was less than for bio-oil, probably because the steam gasification reactivity of char in the slurry was so small that the char remained unconverted. Thus, the unconverted carbon seemed to accumulate during the gasification. Gasification temperature also affected the carbon conversion to gas in the slurry steam gasification. At a temperature of 815°C, the carbon conversion to gas reached 70%. The unconverted carbon was equivalent to the amount of char in the slurry. The char apparently remained unconverted while the bio-oil fraction seemed to be gasified at a high degree of conversion. Steam conversion analysis revealed that catalyst is necessary for steam to become involved in the gasification and yield more H2. Without catalyst, steam was hardly involved in the gasification reaction at the temperatures tested. H2O/C and space velocity of feed did not clearly affect the product gas yields. From the kinetic study in Chapter 2, the reactivity of char from bio-oil/char slurry was generally about 38% less than for Original Char. Considering the carbon conversion to gas hardly exceeds 70% which is equivalent to carbon amount of char in the slurry, steam Chapter 6 Conclusions and suggestions for further work 117 gasification of the slurry can be regarded as a combination of fast gasification of the reactive bio- oil with high conversion to gas, and low extent of reaction with the char. Char gasification controls the kinetics, and use of reaction kinetics for char is the key of the system design. Therefore, the gasifier system should be designed with more focus on use of solid carbon rather than gasifying only liquid and/or gas. The dual-bed gasifier/combustor system seems to be a useful configuration for this situation. The experimental results were compared with the kinetically modified equilibrium model as done by Li (2002). The model took kinetic restriction from unconverted carbon and hydrocarbons in the reaction system into account. Product gas yields from catalytic gasification were very close to those predicted using the model, while product gas yields from non-catalytic gasification were lower in H2 and higher in CO, and thus, did not agree with the model calculations. Therefore, the gasification of bio-oil and bio-oil/char slurry can be reasonably predicted by the model, once the kinetic parameter (carbon conversion, and hydrocarbon yields) are determined empirically. Using the kinetically modified equilibrium model, a mass and energy balance were calculated for a dual-bed gasifier system with slurries of various char concentrationand H2O/C ratios (Chapter 5). Heat of combustion from unconverted carbon in the separate combustor can be transferred to the gasifier and/or the steam generator. This can contribute to the operating energy requirements for endothermic steam gasification. The higher char content in slurry increases bed material circulation rate, and thus the heat transfer from the combustor to the gasifier for fixed air ratio in the combustor. Energy requirement is sensitve to H2O/C ratio since the latent heat of water cannot be recovered in this study. Conditions of lower water feed rate Chapter 6 Conclusions and suggestions for further work 118 lead to a more efficient process design because it saves latent heat recovery. Additional effort should be made for heat integration to improve the process including heat recovery of latent heat of water in the product gas. 6.2 Recommended future work Further studies on important factors for continuous operation of the slurry gasifier should be done in the future. (1) Effect of char content in bio-oil/char slurry on gasification properties The char content in bio-oil/char slurry may be determined at the production stage by how much of the pyrolysis char is required for the slurry itself and the other purposes (i.e. soil improvement for agriculture (Spokas et al., 2009)). For flexible reactor design with varied char content in the slurry, the effect of Slurry Char content on gasification properties should be studied. Tar sampling should be incorporated into this work. (2) Experimental study using dual-bed gasifier In the present study, it is noted that unconverted carbon from the gasifier should be used to generate heat, for example in a dual-bed gasifier. Experimental gasification study with a dual-bed gasifier is necessary to establish the feasibility of the process. (3) Slurry feeding system design The present study utilized an atomizer surrounded by a cooling jacket. Atomization was adequate for short duration runs. However, a better feeding system is needed for long duration, stable feeding of the slurry. From the experience of the gasification experiment, the feed system should be equipped with a device which mechanically removes solid Chapter 6 Conclusions and suggestions for further work 119 carbon or high viscosity feedstock at the end of feed tube, because feedstock plugging was the main problem during the experiments. Even using a cooling jacket, plugging by carbon deposition occurred at the end of atomizer, resulting in a pressure increase in the feed line. Developing a better feeding device might have a positive impact on future work using slurry. Chapter 6 Conclusions and suggestions for further work 120 6.3 References Dinjus, E., Henrich, E. and Weirich, F. (2004) A two stage process for synfuel from biomass. in: IEA bioenergy agreement task 33: Thermal gasification of biomass, task meeting, Vienna, May 3–5. Henrich, E. (2005) Clean syngas from biomass pressurized entrained flow gasification of slurries from fast pyrolysis. in: SYNBIOS - Second generation automotive biofuel conference, Stockholm, Sweden, May 18–20. Li, X. (2002) Biomass gasification in a circulating fluidized bed. PhD thesis, The University of British Columbia, Vancouver. Spokas, K. A., Koskinen, W. C., Baker, J. M. and Reicosky, D. C. (2009) Impacts of woodchip biochar additions on greenhouse gas production and sorption/degradation of two herbicides in a Minnesota soil. Chemosphere 77, 574-581. 121 APPENDICES 122 APPENDIX A Research Note – CO2 Gasification Reactivity of Fast Pyrolysis Char A.1 Introduction In Chapter 2, the gasification reactivity of bio-oil/char slurry, applicable to a steam blown fluidized bed gasifier operating at temperatures of 800–1200°C has been investigated. A dual- bed gasifier system proposed in Chapters 3–5 has a combustor which burns unconverted char in the gasifier. Recycling CO2 produced from the combustor back to itself or the gasifier may allow the CO2 convert into CO reacting with carbon. For the case of using CO2 as a reactant for char gasification, char reactivity in CO2 gasification is analyzed. Thus, the temperature effect on CO2 gasification rate is analyzed. The activation energy is determined and compared with values from the literature, while the reactivity is compared with steam gasification. A.2 Experimental The char used for the present work was made from biomass by fast pyrolysis at Dynamotive Energy Systems corporation. It is noted that the char used in this study was different from the one used in Chapters 2–4. Char samples are from different process and feedstock: the same property cannot be expected. Table A.1 shows the ultimate analysis of the char used for the present work. Char was crushed and sieved to a particle size < 150 m. Appendix A Research note – CO2 gasification reactivity of fast pyrolysis char 123 Table A.1 Ultimate analysis and moisture content of char C (%) H (%) O (%, by diff.) Ash (%) Moisture (%wet) 76.4 6.5 14.8 2.4 1.7 The char was gasified with steam in a thermogravimetric analyzer (TGA) (TA instruments Q600), which consisted of a horizontal balance beam holding a sample pan with a thermocouple in contact with the pan. The char (ca. 5 mg) was placed on an alumina pan, dried at 110°C for 5 minutes in H2, and then heated to the gasification temperature (750–900°C) at a heating rate of 50°C/min. The final temperature was maintained for 5-15 minutes while CO2 was injected into the TGA furnace. CO2 was mixed with H2 in the furnace and reacted with the char. The CO2 partial pressure during the gasification was 33 kPa under total pressure of 100 kPa. The total gas flow rate for each gasification temperature was set at 100 ml/min. A.3 Treatment of experimental results In the present study, the char reactivity at a given time was defined as: (A.1) The degree of conversion, X(t) was obtained by: (A.2) Combining Equations A.1 and A.2 gave reactivity as a function of degree of conversion:   dt wtwd wtw tr f f    )( )( 1 )( f f ww wtw tX    0 )( 1)( Appendix A Research note – CO2 gasification reactivity of fast pyrolysis char 124 (A.3) In this study, steam gasification reactivity of chars was evaluated using Equation A.3. Activation energy for CO2 gasification reactivity of the char at X=0.5 was obtained according to a reaction model, (A.4) A.4 Results and discussion Figure A.1 shows the reactivity of the char at different gasification temperatures. The reactivity highly depends on the temperature. Figure A.2 shows the Arrhenius type plot of the reactivity at 50% conversion for the temperature range of 750–900°C. Since the data were taken at one steam partial pressure, pressure dependency on the reactivity was not analyzed. Therefore, only activation energy E was determined and compared. Using Equation A.4, the activation energy was determined as E=186 kJ/mol. The activation energy is comparable but smaller than values from literature (Table A.2). This is probably due to the smaller flow rate of reactant gas in the TGA furnace causing insufficient dispersion of converted gas from the sample, thus inhibiting the gasification, especially at higher temperatures. dt dX X Xr   1 1 )(        T E kr R exp 0 Appendix A Research note – CO2 gasification reactivity of fast pyrolysis char 125 Table A.2 Activation energy for CO2 gasification: determined and literature value for comparison Source Temperature range Char origin E (kJ mol -1 ) This work (750–900°C) Fast pyrolysis of wood 186 Barrio and Hustad, (2000) (750–950°C) Birch 215 Risnes et al., (2000) (700–1000°C) Wheat straw 205.6 (700–1000°C) Spruce 219.9 Groeneveld and van Swaaij, (1980) (800–1000°C) Deal 217.1 A.5 Comparison with steam gasification reactivity The CO2 gasification reactivity was compared to the steam gasification reactivity. The char was gasified in the same manner reported in Table A.3. CO2 gasification reactivity 50% conversion (X=0.5) was 0.0011 s -1 , and the steam gasification reactivity at 900°C, 30 kPa steam and 50% conversion (X=0.5) was 0.0021 s -1 . The reactivity ratio of steam gasification to CO2 gasification was 1.9. It can be expected that the reactivity of both steam and CO2 gasification of char at the same gasification condition is of the same order of magnitude. Table A.3 Gasification conditions for reactivity analysis in TGA (for comparison between steam and CO2) Carrier gas Temperature Reactant gas pressure CO2 gasification He 900°C 33 kPa Steam gasification N2 900°C 30 kPa Appendix A Research note – CO2 gasification reactivity of fast pyrolysis char 126 A.6 Conclusion Reactivity of char CO2 gasification was studied and compared with that of steam gasification. The activation energy was also determined and compared. Since the reactivity ratio of steam and CO2 gasification of the char was 1.9, general reactivities for both steam and CO2 gasification are expected to be of the same order of magnitude. Figure A.1 Effect of temperature on char reactivity in CO2 gasification 0.0000 0.0005 0.0010 0.0015 0.0020 0 0.2 0.4 0.6 0.8 1 r, s -1 Conversion, X 900°C 850°C 800°C 750°C Appendix A Research note – CO2 gasification reactivity of fast pyrolysis char 127 Figure A.2 Arrhenius type plot of char reactivity in CO2 gasification -10 -9 -8 -7 -6 0.80 0.85 0.90 0.95 1.00 ln r, s -1 1/T 103, K-1 Appendix A Research note – CO2 gasification reactivity of fast pyrolysis char 128 A.7 References Barrio, M. and Hustad, J. E. (2000) CO2 gasification of birch and the effect of CO inhibition on the calculation of chemical kinetics. In: Bridgwater AV editor. Proceedings of the Conference: Progress in Thermochemical Biomass Conversion, Tyrol, Austria, pp. 47– 60 Groeneveld, M. J. and van Swaaij, W. P. M. (1980) 39 Gasification of char particles with CO2 and H2O. Chemical Engineering Science 35, 307-313. Risnes, H., Sørensen, L. H. and Hustad, J. E. (2000) CO2 reactivity of chars from wheat, spruce and coal. In: Bridgwater AV editor. Proceedings of the Conference: Progress in Thermochemical Biomass Conversion, Tyrol, Austria, pp. 61–72. 129 APPENDIX B Material and Energy Balance Sheet, and Degrees of Freedom Analysis B.1 Calculation sheets for mass and energy balance for Chapter 5 Following tables are calculation sheets for mass and energy balance of a dual-bed gasifier discussed in Chapter 5. 1 3 0 A p p en d ix B . M a teria l a n d E n erg y B a la n ce S h eet, a n d D eg rees o f F reed o m A n a lysis fo r C h a p ter 5 Table B.1 Material and energy balance at H2O/C=5.5, char content=10 wt%, and carbon conversion of 83% Component Stream M 1 2 3 4 5 6 7 8 9 10 11 12 kg/kmol Flow (mol/h) H2 2.016 0.0 0.0 0.0 0.0 0.0 59.0 0.0 0.0 59.0 0.0 0.0 0.0 CO 28.010 0.0 0.0 0.0 0.0 0.0 8.6 0.0 0.0 8.6 0.0 0.0 0.0 CO2 44.010 0.0 0.0 0.0 0.0 0.0 22.8 0.0 0.0 22.8 0.0 6.5 6.5 H2O gas 18.015 0.0 0.0 105.9 136.8 195.4 170.3 0.0 0.0 170.3 0.0 0.0 0.0 H2O liquid 18.015 0.0 195.4 89.5 58.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry (CH1.2124O0.4765·0.2934H2O) 26.407 37.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 C (solid) 12.0107 0.0 0.0 0.0 0.0 0.0 0.0 6.5 0.0 0.0 0.0 0.0 0.0 N2 (Air) 28.0134 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 36.5 36.5 36.5 O2 (Air) 31.9988 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 9.7 3.2 3.2 Bed material (Al2O3) 102.00 0.0 0.0 0.0 0.0 0.0 0.0 117.7 117.7 0.0 0.0 0.0 0.0 Total kg/h 1.00 3.52 3.52 3.52 3.52 4.43 12.08 12.00 4.43 1.33 1.41 1.41 Phase L L G+L G+L G G S S G G G G Pressure kPa(abs) 100 100 100 100 100 100 100 100 100 100 100 100 Temperature °C 25 25 100 100 850 850 850 950 300 25 950 150 Temperature K 298 298 373 373 1123 1123 1123 1223 573 298 1223 423 Volume m3/h 0.0 0.0 3.3 4.2 18.2 24.3 0.0 0.0 12.4 1.1 4.7 1.6 Enthalpy H-H298 kJ/h 0 0 5436 6700 14675 15352 9993 11102 9916 0 1444 179 Cp mean kJ/kmol K - 75.4 53.3 46.7 42.5 40.6 97.8 102.0 35.2 29.2 36.5 31.6 Heat exchanger A B Bed material circulation Steam heater Product gas Water Exhaust gas Steam 6 7 4 Temperature IN °C 850 25 950 100 850 950 100 K 1123 298 1223 373 1123 1223 373 Temperature OUT °C 300 100 150 100 950 850 850 K 573 373 423 373 1223 1123 1123 Heat transfer kJ/h -5437 5436 -1265 1264 1108 -1109 7976 W -1510 1510 -351 351 308 -308 2215 1 3 1 A p p en d ix B . M a teria l a n d E n erg y B a la n ce S h eet, a n d D eg rees o f F reed o m A n a lysis fo r C h a p ter 5 Table B.2 Material and energy balance at H2O/C=5.5, char content=15 wt%, and carbon conversion of 77% Component Stream M 1 2 3 4 5 6 7 8 9 10 11 12 kg/kmol Flow (mol/h) H2 2.016 0.0 0.0 0.0 0.0 0.0 57.2 0.0 0.0 57.2 0.0 0.0 0.0 CO 28.010 0.0 0.0 0.0 0.0 0.0 7.8 0.0 0.0 7.8 0.0 0.0 0.0 CO2 44.010 0.0 0.0 0.0 0.0 0.0 22.3 0.0 0.0 22.3 0.0 9.0 9.0 H2O gas 18.015 0.0 0.0 107.8 151.0 202.8 178.5 0.0 0.0 178.5 0.0 0.0 0.0 H2O liquid 18.015 0.0 202.8 95.0 51.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry (CH1.1295O0.4370·0.2841H2O) 25.569 39.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 C (solid) 12.0107 0.0 0.0 0.0 0.0 0.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 N2 (Air) 28.0134 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 50.9 50.9 50.9 O2 (Air) 31.9988 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 13.5 4.5 4.5 Bed material (Al2O3) 102.00 0.0 0.0 0.0 0.0 0.0 0.0 164.3 164.3 0.0 0.0 0.0 0.0 Total kg/h 1.00 3.65 3.65 3.65 3.65 4.53 16.86 16.76 4.53 1.86 1.97 1.97 Phase L L G+L G+L G G S S G G G G Pressure kPa(abs) 100 100 100 100 100 100 100 100 100 100 100 100 Temperature °C 25 25 100 100 850 850 850 950 300 25 950 150 Temperature K 298 298 373 373 1123 1123 1123 1223 573 298 1223 423 Volume m3/h 0.0 0.0 3.3 4.7 18.9 24.8 0.0 0.0 12.7 1.6 6.6 2.3 Enthalpy H-H298 kJ/h 0 0 5558 7322 15234 15890 13951 15499 10332 0 2015 250 Cp mean kJ/kmol K - 75.4 53.8 44.8 42.5 40.7 97.8 102.0 35.3 29.2 36.5 31.6 Heat exchanger A B Bed material circulation Steam heater Product gas Water Exhaust gas Steam 6 7 4 Temperature IN °C 850 25 950 100 850 950 100 K 1123 298 1223 373 1123 1223 373 Temperature OUT °C 300 100 150 100 950 850 850 K 573 373 423 373 1223 1123 1123 Heat transfer kJ/h -5558 5558 -1765 1764 1547 -1548 7912 W -1544 1544 -490 490 430 -430 2198 1 3 2 A p p en d ix B . M a teria l a n d E n erg y B a la n ce S h eet, a n d D eg rees o f F reed o m A n a lysis fo r C h a p ter 5 Table B.3 Material and energy balance at H2O/C=5.5, char content=20 wt%, and carbon conversion of 70% Component Stream M 1 2 3 4 5 6 7 8 9 10 11 12 kg/kmol Flow (mol/h) H2 2.016 0.0 0.0 0.0 0.0 0.0 54.6 0.0 0.0 54.6 0.0 0.0 0.0 CO 28.010 0.0 0.0 0.0 0.0 0.0 6.8 0.0 0.0 6.8 0.0 0.0 0.0 CO2 44.010 0.0 0.0 0.0 0.0 0.0 21.4 0.0 0.0 21.4 0.0 12.1 12.1 H2O gas 18.015 0.0 0.0 109.5 167.6 210.2 187.7 0.0 0.0 187.7 0.0 0.0 0.0 H2O liquid 18.015 0.0 210.2 100.7 42.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry (CH1.0517O0.4000·0.2754H2O) 24.783 40.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 C (solid) 12.0107 0.0 0.0 0.0 0.0 0.0 0.0 12.1 0.0 0.0 0.0 0.0 0.0 N2 (Air) 28.0134 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 68.5 68.5 68.5 O2 (Air) 31.9988 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 18.2 6.1 6.1 Bed material (Al2O3) 102.00 0.0 0.0 0.0 0.0 0.0 0.0 220.8 220.8 0.0 0.0 0.0 0.0 Total kg/h 1.00 3.79 3.79 3.79 3.79 4.62 22.67 22.52 4.62 2.50 2.65 2.65 Phase L L G+L G+L G G S S G G G G Pressure kPa(abs) 100 100 100 100 100 100 100 100 100 100 100 100 Temperature °C 25 25 100 100 850 850 850 950 300 25 950 150 Temperature K 298 298 373 373 1123 1123 1123 1223 573 298 1223 423 Volume m3/h 0.0 0.0 3.4 5.2 19.6 25.3 0.0 0.0 12.9 2.1 8.8 3.0 Enthalpy H-H298 kJ/h 0 0 5670 8042 15793 16455 18753 20833 10785 0 2709 336 Cp mean kJ/kmol K - 75.4 54.2 42.6 42.5 40.8 97.8 102.0 35.4 29.2 36.5 31.6 Heat exchanger A B Bed material circulation Steam heater Product gas Water Exhaust gas Steam 6 7 4 Temperature IN °C 850 25 950 100 850 950 100 K 1123 298 1223 373 1123 1223 373 Temperature OUT °C 300 100 150 100 950 850 850 K 573 373 423 373 1223 1123 1123 Heat transfer kJ/h -5670 5670 -2374 2372 2080 -2081 7751 W -1575 1575 -659 659 578 -578 2153 1 3 3 A p p en d ix B . M a teria l a n d E n erg y B a la n ce S h eet, a n d D eg rees o f F reed o m A n a lysis fo r C h a p ter 5 Table B.4 Material and energy balance at H2O/C=5.5, char content=25 wt%, and carbon conversion of 64% Component Stream M 1 2 3 4 5 6 7 8 9 10 11 12 kg/kmol Flow (mol/h) H2 2.016 0.0 0.0 0.0 0.0 0.0 52.2 0.0 0.0 52.2 0.0 0.0 0.0 CO 28.010 0.0 0.0 0.0 0.0 0.0 6.0 0.0 0.0 6.0 0.0 0.0 0.0 CO2 44.010 0.0 0.0 0.0 0.0 0.0 20.6 0.0 0.0 20.6 0.0 15.0 15.0 H2O gas 18.015 0.0 0.0 111.3 183.1 217.7 196.6 0.0 0.0 196.6 0.0 0.0 0.0 H2O liquid 18.015 0.0 217.7 106.4 34.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry (CH0.9786O0.3651·0.2671H2O) 24.043 41.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 C (solid) 12.0107 0.0 0.0 0.0 0.0 0.0 0.0 15.0 0.0 0.0 0.0 0.0 0.0 N2 (Air) 28.0134 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 84.7 84.7 84.7 O2 (Air) 31.9988 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 22.5 7.5 7.5 Bed material (Al2O3) 102.00 0.0 0.0 0.0 0.0 0.0 0.0 272.8 272.8 0.0 0.0 0.0 0.0 Total kg/h 1.00 3.92 3.92 3.92 3.92 4.72 28.00 27.82 4.72 3.09 3.27 3.27 Phase L L G+L G+L G G S S G G G G Pressure kPa(abs) 100 100 100 100 100 100 100 100 100 100 100 100 Temperature °C 25 25 100 100 850 850 850 950 300 25 950 150 Temperature K 298 298 373 373 1123 1123 1123 1223 573 298 1223 423 Volume m3/h 0.0 0.0 3.5 5.7 20.3 25.7 0.0 0.0 13.1 2.7 10.9 3.8 Enthalpy H-H298 kJ/h 0 0 5785 8719 16352 17012 23166 25737 11226 0 3350 415 Cp mean kJ/kmol K - 75.4 54.6 40.7 42.5 41.0 97.8 102.0 35.4 29.2 36.5 31.6 Heat exchanger A B Bed material circulation Steam heater Product gas Water Exhaust gas Steam 6 7 4 Temperature IN °C 850 25 950 100 850 950 100 K 1123 298 1223 373 1123 1223 373 Temperature OUT °C 300 100 150 100 950 850 850 K 573 373 423 373 1223 1123 1123 Heat transfer kJ/h -5786 5785 -2934 2934 2571 -2570 7633 W -1607 1607 -815 815 714 -714 2120 1 3 4 A p p en d ix B . M a teria l a n d E n erg y B a la n ce S h eet, a n d D eg rees o f F reed o m A n a lysis fo r C h a p ter 5 Table B.5 Material and energy balance at H2O/C=5.5, char content=30 wt%, and carbon conversion of 56% Component Stream M 1 2 3 4 5 6 7 8 9 10 11 12 kg/kmol Flow (mol/h) H2 2.016 0.0 0.0 0.0 0.0 0.0 48.1 0.0 0.0 48.1 0.0 0.0 0.0 CO 28.010 0.0 0.0 0.0 0.0 0.0 4.8 0.0 0.0 4.8 0.0 0.0 0.0 CO2 44.010 0.0 0.0 0.0 0.0 0.0 19.1 0.0 0.0 19.1 0.0 18.9 18.9 H2O gas 18.015 0.0 0.0 112.8 203.1 225.1 207.2 0.0 0.0 207.2 0.0 0.0 0.0 H2O liquid 18.015 0.0 225.1 112.4 22.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry (CH0.9097O0.33323·0.2594H2O) 23.347 42.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 C (solid) 12.0107 0.0 0.0 0.0 0.0 0.0 0.0 18.9 0.0 0.0 0.0 0.0 0.0 N2 (Air) 28.0134 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 106.5 106.5 106.5 O2 (Air) 31.9988 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 28.3 9.4 9.4 Bed material (Al2O3) 102.00 0.0 0.0 0.0 0.0 0.0 0.0 343.1 343.1 0.0 0.0 0.0 0.0 Total kg/h 1.00 4.06 4.06 4.06 4.06 4.81 35.22 34.99 4.81 3.89 4.12 4.12 Phase L L G+L G+L G G S S G G G G Pressure kPa(abs) 100 100 100 100 100 100 100 100 100 100 100 100 Temperature °C 25 25 100 100 850 850 850 950 300 25 950 150 Temperature K 298 298 373 373 1123 1123 1123 1223 573 298 1223 423 Volume m3/h 0.0 0.0 3.5 6.3 21.0 26.1 0.0 0.0 13.3 3.3 13.7 4.7 Enthalpy H-H298 kJ/h 0 0 5886 9576 16911 17620 29137 32370 11734 0 4214 522 Cp mean kJ/kmol K - 75.4 55.1 38.2 42.5 41.1 97.8 102.0 35.5 29.2 36.5 31.6 Heat exchanger A B Bed material circulation Steam heater Product gas Wate r Exhaust gas Stea m 6 7 4 Temperature IN °C 850 25 950 100 850 950 100 K 1123 298 1223 373 1123 1223 373 Temperature OUT °C 300 100 150 100 950 850 850 K 573 373 423 373 1223 1123 1123 Heat transfer kJ/h -5885 5886 -3692 3690 3234 -3233 7335 W -1635 1635 -1025 1025 898 -898 2038 1 3 5 A p p en d ix B . M a teria l a n d E n erg y B a la n ce S h eet, a n d D eg rees o f F reed o m A n a lysis fo r C h a p ter 5 Table B.6 Material and energy balance at H2O/C=1.0, char content=20 wt%, and carbon conversion of 70% Component Stream M 1 2 3 4 5 6 7 8 9 10 11 12 kg/kmol Flow (mol/h) H2 2.016 0.0 0.0 0.0 0.0 0.0 41.5 0.0 0.0 41.5 0.0 0.0 0.0 CO 28.010 0.0 0.0 0.0 0.0 0.0 19.8 0.0 0.0 19.8 0.0 0.0 0.0 CO2 44.010 0.0 0.0 0.0 0.0 0.0 8.4 0.0 0.0 8.4 0.0 12.2 12.2 H2O gas 18.015 0.0 0.0 28.9 28.9 28.9 19.3 0.0 0.0 19.3 0.0 0.0 0.0 H2O liquid 18.015 0.0 28.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry (CH1.0517O0.4000·0.2754H2O) 24.783 40.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 C (solid) 12.0107 0.0 0.0 0.0 0.0 0.0 0.0 12.2 0.0 0.0 0.0 0.0 0.0 N2 (Air) 28.0134 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 68.6 68.6 68.6 O2 (Air) 31.9988 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 18.2 6.1 6.1 Bed material (Al2O3) 102.00 0.0 0.0 0.0 0.0 0.0 0.0 221.2 221.2 0.0 0.0 0.0 0.0 Total kg/h 1.00 0.52 0.52 0.52 0.52 1.36 22.71 22.56 1.36 2.50 2.65 2.65 Phase L L G G G G S S G G G G Pressure kPa(abs) 100 100 100 100 100 100 100 100 100 100 100 100 Temperature °C 25 25 432 850 850 850 850 950 300 25 950 150 Temperature K 298 298 705 1123 1123 1123 1123 1223 573 298 1223 423 Volume m3/h 0.0 0.0 1.7 2.7 2.7 8.3 0.0 0.0 4.2 2.2 8.8 3.1 Enthalpy H-H298 kJ/h 0 0 1685 2167 2167 3304 18785 20869 1620 0 2714 336 Cp mean kJ/kmol K - 75.4 37.6 42.5 42.5 36.2 97.8 102.0 32.6 29.2 36.5 31.6 Heat exchanger A B Bed material circulation Steam heater Product gas Water Exhaust gas Steam 6 7 4 Temperature IN °C 850 25 950 100 850 950 850 K 1123 298 1223 373 1123 1223 1123 Temperature OUT °C 300 432 796 850 950 850 850 K 573 705 1069 1123 1223 1123 1123 Heat transfer kJ/h -1685 1685 -482 483 2083 -2084 0 W -468 468 -134 134 579 -579 0 1 3 6 A p p en d ix B . M a teria l a n d E n erg y B a la n ce S h eet, a n d D eg rees o f F reed o m A n a lysis fo r C h a p ter 5 Table B.7 Material and energy balance at H2O/C=3.0, char content=20 wt%, and carbon conversion of 70% Component Stream M 1 2 3 4 5 6 7 8 9 10 11 12 kg/kmol Flow (mol/h) H2 2.016 0.0 0.0 0.0 0.0 0.0 50.7 0.0 0.0 50.7 0.0 0.0 0.0 CO 28.010 0.0 0.0 0.0 0.0 0.0 10.7 0.0 0.0 10.7 0.0 0.0 0.0 CO2 44.010 0.0 0.0 0.0 0.0 0.0 17.5 0.0 0.0 17.5 0.0 12.1 12.1 H2O gas 18.015 0.0 0.0 69.8 109.5 109.5 90.8 0.0 0.0 90.8 0.0 0.0 0.0 H2O liquid 18.015 0.0 109.5 39.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry (CH1.0517O0.4000·0.2754H2O) 24.783 40.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 C (solid) 12.0107 0.0 0.0 0.0 0.0 0.0 0.0 12.1 0.0 0.0 0.0 0.0 0.0 N2 (Air) 28.0134 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 68.5 68.5 68.5 O2 (Air) 31.9988 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 18.2 6.1 6.1 Bed material (Al2O3) 102.00 0.0 0.0 0.0 0.0 0.0 0.0 220.8 220.8 0.0 0.0 0.0 0.0 Total kg/h 1.00 1.97 1.97 1.97 1.97 2.81 22.67 22.52 2.81 2.50 2.65 2.65 Phase L L G+L G G G S S G G G G Pressure kPa(abs) 100 100 100 100 100 100 100 100 100 100 100 100 Temperature °C 25 25 100 296 850 850 850 950 300 25 950 150 Temperature K 298 298 373 569 1123 1123 1123 1223 573 298 1223 423 Volume m3/h 0.0 0.0 2.2 5.2 10.2 15.8 0.0 0.0 8.1 2.1 8.8 3.0 Enthalpy H-H298 kJ/h 0 0 3475 5847 8223 9027 18753 20833 5553 0 2710 336 Cp mean kJ/kmol K - 75.4 49.3 36.0 42.5 39.7 97.8 102.0 34.7 29.2 36.5 31.6 Heat exchanger A B Bed material circulation Steam heater Product gas Water Exhaust gas Steam 6 7 4 Temperature IN °C 850 25 950 100 850 950 296 K 1123 298 1223 373 1123 1223 569 Temperature OUT °C 300 100 150 296 950 850 850 K 573 373 423 569 1223 1123 1123 Heat transfer kJ/h -3475 3475 -2374 2372 2080 -2081 2376 W -965 965 -659 659 578 -578 660 1 3 7 A p p en d ix B . M a teria l a n d E n erg y B a la n ce S h eet, a n d D eg rees o f F reed o m A n a lysis fo r C h a p ter 5 Table B.8 Material and energy balance at H2O/C=8.0, char content=20 wt%, and carbon conversion of 70% Component Stream M 1 2 3 4 5 6 7 8 9 10 11 12 kg/kmol Flow (mol/h) H2 2.016 0.0 0.0 0.0 0.0 0.0 56.4 0.0 0.0 56.4 0.0 0.0 0.0 CO 28.010 0.0 0.0 0.0 0.0 0.0 5.0 0.0 0.0 5.0 0.0 0.0 0.0 CO2 44.010 0.0 0.0 0.0 0.0 0.0 23.2 0.0 0.0 23.2 0.0 12.1 12.1 H2O gas 18.015 0.0 0.0 149.0 207.1 311.0 286.7 0.0 0.0 286.7 0.0 0.0 0.0 H2O liquid 18.015 0.0 311.0 162.0 103.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry (CH1.0517O0.4000·0.2754H2O) 24.783 40.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 C (solid) 12.0107 0.0 0.0 0.0 0.0 0.0 0.0 12.1 0.0 0.0 0.0 0.0 0.0 N2 (Air) 28.0134 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 68.5 68.5 68.5 O2 (Air) 31.9988 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 18.2 6.1 6.1 Bed material (Al2O3) 102.00 0.0 0.0 0.0 0.0 0.0 0.0 220.8 220.8 0.0 0.0 0.0 0.0 Total kg/h 1.00 5.60 5.60 5.60 5.60 6.44 22.67 22.52 6.44 2.50 2.65 2.65 Phase L G+L G G G G S S G G G G Pressure kPa(abs) 100 100 100 100 100 100 100 100 100 100 100 100 Temperature °C 25 25 100 100 850 850 850 950 300 25 950 150 Temperature K 298 298 373 373 1123 1123 1123 1223 573 298 1223 423 Volume m3/h 0.0 0.0 4.6 6.4 29.0 34.7 0.0 0.0 17.7 2.1 8.8 3.0 Enthalpy H-H298 kJ/h 0 0 7855 10228 23363 23959 18753 20833 16104 0 2709 336 Cp mean kJ/kmol K - 75.4 56.0 48.1 42.5 41.3 97.8 102.0 35.6 29.2 36.5 31.6 Heat exchanger A B Bed material circulation Steam heater Product gas Water Exhaust gas Steam 6 7 4 Temperature IN °C 850 25 950 100 850 950 100 K 1123 298 1223 373 1123 1223 373 Temperature OUT °C 300 100 150 100 950 850 850 K 573 373 423 373 1223 1123 1123 Heat transfer kJ/h -7855 7855 -2374 2372 2080 -2081 13136 W -2182 2182 -659 659 578 -578 3649 Appendix B. Material and Energy Balance Sheet, and Degrees of Freedom Analysis for Chapter 5 138 B.2 Degrees of freedom in the dual-bed gasifier system Species: 9 species (H2, CO, CO2, H2O, N2, O2, C(solid), Bed material, Slurry) General constraints: Excess amount of air for the combustor is introduced. Temperatures of water and product gas after the condenser are the same. Entire process Nv = 5(Nsp + 2) + 1 = 5(9 + 2) + 1 = 56 (Number of flows × (Nsp + T + P) +1 for energy balance) Nr: Material balance (C, H, N, O) 4 Energy balance 1 Specifications: Flow 1 (all 9 concentrations) 8 Flow 2 (all 9 concentrations) 8 Flow 9 (5 concentration) 5 Flow 10 (all 9 concentrations) 8 Flow 12 (6 concentrations) 6 Product gas composition is a function of T 1 41 Nd = 56 – 41 15 Appendix B. Material and Energy Balance Sheet, and Degrees of Freedom Analysis for Chapter 5 139 Gasification reactor: Nv = 5(Nsp + 2) + 1 = 5(9 + 2) + 1 = 56 (Number of flows × (Nsp + T + P) +1 for energy balance) Nr: Material balances (C, H, N, O, BM) 5 Energy balance 1 Specifications: Flow 1 (all 9 concentration) 8 Flow 5 (all 9 concentrations) 8 Flow 6 (Slurry, N2, O2, C and BM are determined) 5 Flow 7 (7 concentrations except C and BM) 7 Flow 8 (all 9 concentrations) 8 T5=T6=T7 2 44 Nd = 56 – 44 = 12 Combustor: Nv = 4(Nsp + 2) + 1 = 4(9 + 2) + 1 = 45 (Number of flows × (Nsp + T + P) +1 for energy balance) Nr: Material balances (C, H, N, O, BM) 5 Energy balance 1 Specifications: Appendix B. Material and Energy Balance Sheet, and Degrees of Freedom Analysis for Chapter 5 140 Flow 7 (7 concentrations except C and BM) 7 Flow 8 (all 9 concentrations) 8 Flow 10 (concentration of N2, O2 and others) 8 Flow 11 (H2=CO=H2O=BM=C=Slurry=0) 6 T8=T11 1 36 Nd = 45 – 36 = 9 A: Heat exchanger 1 Nv = 4(Nsp + 2) + 1 = 4(9 + 2) + 1 = 45 (Number of flows × (Nsp + T + P) +1 for energy balance) Nr: Material balances (2 streams) 2 Energy balance 1 Specifications: Composition of inlet and outlet streams the same 2(Nsp-1) 16 Composition inlet Flow 9 (N2=O2=C=BM=Slurry=0) 5 Composition inlet Flow 2 (all 9 concentration) 8 32 Nd = 45 – 32 = 13 B: Heat exchanger 2 Nv = 4(Nsp + 2) + 1 = 4(9 + 2) + 1 = 45 (Number of flows × (Nsp + T + P) +1 for energy balance) Appendix B. Material and Energy Balance Sheet, and Degrees of Freedom Analysis for Chapter 5 141 Nr: Material balances (2 streams) 2 Energy balance 1 Specifications: Composition of inlet and outlet streams the same 2(Nsp-1) 16 Composition inlet Flow 3 (all 9 concentration) 8 Composition inlet Flow 11 (6 concentration) 6 33 Nd = 45 – 33 = 12 B.3 Nomenclature BM Bed material Nd Number of degrees of freedom Nr Number of independent constraints Nsp Number of chemical species Nv Number of variables 142 APPENDIX C Details of Apparatus Figure C.1 Locations of thermocouples and pressure transducers Condenser Fluidized bed reactor Condensate collector Steam generator Cooling jacket + Atomizer Micro-GC Filter Flow meter After burner To Vent Air Pump Rotameters N2 Pump Sampling for GC/MS Bio-oil Slurry H2O H2 Air N2 Rotameters Ice trap To Vent PT1 TC2 PT2 TC3 TC4 TC5 TC6 TC7 TC8 TC9 PT3 PT4 PT3 TCT TC10 TC11 TC12 TC1 Appendix C Details of apparatus 143 Figure C.2 Detail of gasification reactor assembly Figure Drawing of reactor (assembled) Bio-oil or slurry Cooling water out Cooling water in N2/Air In te rn a l c y c lo n e H e a ti n g t a p e N2 H2 Air Steam from steam generator Product gas Relief valve T P P T T T T T P Reactor top flange Graphite gasket Graphite gasket Graphite gasket Distribution plate Distribution plate Reactor bottom flange Graphite gasket Graphite gasket #100 mesh Appendix C Details of apparatus 144 Figure C.3 Drawing of reactor top Appendix C Details of apparatus 145 Figure C.4 Drawing of reactor bottom Appendix C Details of apparatus 146 Figure C.5 Drawing of flange part Appendix C Details of apparatus 147 Figure C.6 Drawing of distribution plate Appendix C Details of apparatus 148 Figure C.7 Drawing of reactor lid for the bottom Appendix C Details of apparatus 149 Figure C.8 Drawing of reactor lid for the top Appendix C Details of apparatus 150 Figure C.9 Drawing of graphite gasket Appendix C Details of apparatus 151 Figure C.10 Drawing of internal cyclone Appendix C Details of apparatus 152 Figure C.12 Drawing of cooling jacket Figure C.11 Drawing of atomizer slot Appendix C Details of apparatus 153 Figure C.13 Drawing of spray nozzle adaptor Figure C.14 Aircap and aircap body, assembled with spray nozzle adaptor with 1/8-inch-O.D. feedline Figure C.15 Spray nozzle (former) assemble of Swagelok fittings with 1/16-inch-O.D. feed line Fitting for Aircap body 1/4”OD 316SS tubing 24” Aircap body Aircap Appendix C Details of apparatus 154 C.1 Recommendations for atomizer design In this study, several atomizer designs and settings were evaluated to atomize the bio- oil/char slurry. Atomizer from the bottom of the reactor Atomizer was an assembly of Swagelok fittings having a 1/16-inch hole at the end. 1/16- inch-O.D. stainless steel tube was used for the slurry feedline, and a 1/4-inch-O.D. stainless steel tube was used for the outer tube in which N2 or air was fed as atomizer gas. The atomizer line was placed from the bottom of the reactor go into the bed material through the distribution plate. Due to the limited space at the bottom of the reactor, no cooling devices were installed for the atomizer. Performance The feed line was plugged easily by: ■ Bed material because atomizer outlet hole faces upward into the bed material ■ Thermal degradation of bio-oil and slurry which yielded either high viscosity fluid or solid carbon ■ Char from the slurry due to the small diameter of the feedline tube Atomizer from the side of the reactor with cooling jacket To solve the plugging problems, a new atomizer was designed with following features: ■ An airbrush nozzle was used for atomizer nozzle in place of the single outlet hole. ■ A cooling jacket was installed to cover the atomizer fully to prevent feedstock thermal degradation in the feedline. Appendix C Details of apparatus 155 ■ 1/8-inch-O.D. feedline tubing was used to replace the 1/16-inch tube and prevent plugging by slurry. Recommendation It is essential that the slurry be kept cool before it reaches the atomizer, to prevent plugging in the line or in the atomizer itself. If an atomizer style is chosen as feeding method, cooling device upstream of atomization is necessary. Feeding slurry, which is a high viscosity fluid, needs wide tubing of sufficient diameter. Thus, at least 1/8-inch-O.D. tubing is recommended for the feedline. If the reactor has enough room at the bottom, and enough purge at the atomizer, atomizer could be placed at the bottom of the reactor for reasons of symmetry. A device which removes degraded feedstock and solid carbon in the feedline is also recommended for more stable feed. 156 APPENDIX D Experimental Procedure Before heating up ■ Prepare ice trap ■ Set up micro-GC and connect the gas line ■ Turn on the micro-GC computer and open the controlling software (Galaxy) ■ Set up the micro-GC acquisition sequence ■ Check electronic breakers are ON ■ Open N2 and H2 valves of pressure regulators on gas cylinders ■ Open building air valve on the wall and set the pressure to 100 psi ■ Open building water valve on the wall ■ Open cooling water valve and set to reading of 30 ■ Make sure the 3 way valve after the condenser is open to the flow meter ■ Make sure the stop valve before the afterburner is open ■ Close the valve at the bottom of the liquid collector ■ Turn on the recording computer ■ Open recording software (PDAQVIEW), and start recording ■ Open N2 valves for: ■ atomizer (purging and protect atomizer from heat), set at ~1.5 L/min ■ purging pressure transducers at 5 ml/min ■ purging rapture disc line at 10 ml/min (when sand is used, air can be used for atomizer purging) Appendix D Experimental procedure 157 Preheating Steam generator ■ Set steam generator final temperature to 800°C ■ Wait for 1 hour Turn on after burner ■ Set final temperature to 700°C ■ Open air valve for after burner and set the flow rate at 2 scfm Heating up reactor ■ Set final temperatures of top and bottom furnaces to gasification temperature Catalyst activation (when catalyst is used) ■ Before introducing H2, introduce small amount of water to purge all oxygen from the steam generator and the reactor ■ Open H2 valve at 800 ml/min when the bed temperature reaches 400°C ■ Leave 30 minutes, after the bed temperature reaches gasification temperature Gasification of bio-oil or bio-oil/char slurry ■ Close H2 valve Start feeding ■ Start micro-GC acquisition sequence ■ Turn on water pump ■ Make sure no bubbles are in the water feed line ■ Measure feeding rate by weighing the water, and adjust pump speed to achieve required feeding rate Appendix D Experimental procedure 158 ■ Open and adjust N2 and/or air valve for the atomizer and reactor bottom to required flow rate ■ Turn on feed pump ■ Feed pump is very stable and does not need adjustment ■ Record feed rates of water and feedstock by weighing them periodically ■ Record flow rates of atomizer gases and gas introduced from the reactor bottom periodically ■ Adjust flow meter pressure around 3 psi-g by adjusting the valve before the afterburner to make steady flow to the micro-GC After each gasification condition ■ Feed methanol to wash the feed line ■ Stop feed pump (Keep the atomizer gas flow on) ■ Open air valve to burn residual carbons (note that keep an eye on the reactor temperature, not to exceed 900°C) (once the residual carbons completely burnt out, the temperature drops rapidly) Repeat “Start feeding” with next setting Shutdown ■ Turn off micro-GC ■ Stop feed pump ■ Stop water pump ■ Switch atomizer gas to air and keep the atomizer gas flow on Appendix D Experimental procedure 159 ■ Keep cooling water flow on ■ Stop all the gases and cooling water when all the monitoring temperatures reach ambient temperature ■ Turn off recording and shutdown the computer Emergency shutdown ■ Press emergency shutdown button (that shutdown all furnaces and pumps) ■ Evacuate the room 160 APPENDIX E Flow Meter Calibrations Figure E.1 Calibration of the water pump at 50% stroke (IWAKI metering pump, adjustable stroke, model#: EWB15F1-PC) y = 0.4292x + 0.8968 R² = 0.9993 0 10 20 30 40 50 60 0 10 20 30 40 50 60 70 80 90 100 110 120 130 F ee d r at e [g /m in ] Stroke/min Appendix E Flow meter calibration 161 Figure E.2 Calibration of the pump for bio-oil or bio-oil/char slurry (CHEM-TECH peristaltic pump, model#: CTPD2HS1-PAP1-XXXXX) y = 0.2105x R² = 0.9997 0 5 10 15 20 25 0 10 20 30 40 50 60 70 80 90 100 F lo w r at e [m l/ m in ] Set Value Appendix E Flow meter calibration 162 Figure E.3 Calibration of Air/N2 flow controller for atomizer (air for partial oxidation; N2 for steam gasification) 0 5 10 15 20 25 30 35 0 10 20 30 40 F lo w ra te [ L /m in ] Reading [mm] 30 psi-g 25 psi-g 20 psi-g 15 psi-g 10 psi-g 7.5 psi-g 5.0 psi-g 2.5 psi-g No restriction Appendix E Flow meter calibration 163 Figure E.4 Calibration of the flow controller for air introduced at the bottom of the reactor 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 F lo w r at e [L /m in ] Reading [mm] 207 kPa-g 172 kPa-g 138 kPa-g 103 kPa-g 69 kPa-g 34 kPa-g 0 kPa-g Appendix E Flow meter calibration 164 Figure E.5 Calibration of N2 flow controller for atomizer in partial oxidation 0 1 2 3 4 5 6 7 8 9 0 50 100 150 F lo w r at e [L /m in ] Reading [mm] 30 psi-g 20 psi-g 10 psi-g 0 psi-g Appendix E Flow meter calibration 165 Figure E.6 Calibration of N2 flow controller for purging pressure transducer line at the bottom of the reactor y = 4.47E-05x3 - 3.49E-03x2 + 2.71E-01x + 1.48E+00 R² = 9.99E-01 0 5 10 15 20 0 20 40 60 80 F lo w r at e [m l/ m in ] Reading [mm] #1, N2 purge for pressure transducer (PT3), reactor bed bottom Appendix E Flow meter calibration 166 Figure E.7 Calibration of N2 flow controller for purging pressure transducer line at the top of the reactor y = 1.29E-05x3 - 9.07E-04x2 + 2.34E-01x + 2.20E+00 R² = 9.98E-01 0 5 10 15 20 0 20 40 60 80 F lo w r at e [m l/ m in ] Reading [mm] #2, N2 purge for PT4, reactor top Appendix E Flow meter calibration 167 Figure E.8 Calibration of N2 flow controller for purging rupture disc line y = 3.45E-05x3 + 4.74E-03x2 + 2.68E-01x + 2.03E+00 R² = 1.00E+00 0 10 20 30 40 50 60 0 20 40 60 80 F lo w r at e [m l/ m in ] Reading [mm] #3, N2 purge, rupture disc line Appendix E Flow meter calibration 168 Figure E.9 Calibration of N2 flow controller for H2/N2 mix from the reactor bottom for activating catalyst y = -1.57E-03x3 + 1.44E-01x2 + 1.34E+01x - 2.78E+01 R² = 9.99E-01 0 200 400 600 800 1000 1200 0 20 40 60 80 F lo w r at e [m l/ m in ] Reading [mm] #4, N2 for H2/N2 mix Appendix E Flow meter calibration 169 Figure E.10 Calibration of H2 flow controller for H2/N2 mix from the reactor bottom for activating catalyst y = 1.27E+01x R² = 1.00E+00 0 100 200 300 400 500 600 700 800 900 0 20 40 60 80 F lo w r at e [m l/ m in ] Reading [mm] #5, H2 for H2/N2 mix Appendix E Flow meter calibration 170 Figure E.11 Calibration of N2 flow controller for purging outside the reactor inside the furnaces y = 7.29E-05x3 + 1.49E-02x2 + 9.04E-01x + 8.07E+00 R² = 9.98E-01 0 20 40 60 80 100 120 140 160 180 0 20 40 60 80 F lo w r at e [m l/ m in ] Reading [mm] #6, N2 purge, outside reactor 171 APPENDIX F Location of Thermocouples and Pressure Transducers Table F.1 Location of thermocouples and pressure transducers Channel PC designation Type/Output Model Location 1 PT1 100 mV DC PX309-015GV Steam generator water inlet 2 PT2 100 mV DC PX309-015GV Reactor bottom 3 PT3 100 mV DC PX309-015GV Reactor bed bottom 4 PT4 100 mV DC PX309-015GV Reactor top 5 PT5 1–5 V DC PX309-002G5V Right before flow meter 6 TC1 Type K - Bio-oil Feed 7 TC2 Type K - Steam Generator Exit 8 TC3 Type K - Reactor Bottom 9 TC4 Type K - Reactor Bed 10 TC5 Type K - Reactor Middle 1 11 TC6 Type K - Reactor Middle 2 12 TC7 Type K - Reactor Middle 3 13 TC8 Type K - Reactor Middle 4 14 TC9 Type K - Reactor Top 15 TC10 Type K - Condenser Inlet 16 TC11 Type K - Condenser Exit 17 TC12 Type K - Rupture Disc 18 TCT Type T - Flow meter 19 Gas flow Volumetric 32908-23 After condenser All pressure transducers and thermocouples are from OMEGA Flow meter is from Cole-Parmer 172 APPENDIX G Experimental Data 1 7 3 A p p en d ix G E xp erim en ta l d a ta Table G.1 Experimental data of partial oxidation #1 Run name PO_OC08-1 PO_OC08-2 PO_OC14-1 PO_OC14-2 PO_AU31-1 PO_AU31-2 PO_AU31-3 PO_AU31-4 Feed Slurry Slurry Slurry Slurry Bio-oil Bio-oil Bio-oil Bio-oil Bed material Catalyst Catalyst Catalyst Catalyst Catalyst Catalyst Catalyst Catalyst Gasification temperature (Bed temperature) (°C) 848 848 749 748 842 802 746 758  air ratio - 0.5 0.3 0.5 0.3 0.5 0.3 0.5 0.3 Bed pressure kPa-g 23.2 150.1 19.3 73.4 22.0 33.0 77.0 120.0 Water feed g/min 8.73 8.54 8.71 9.02 8.23 8.33 7.96 8.09 Air Atomizer (measured) L/min 12.0 8.5 11.9 8.6 12.7 7.9 13.6 8.7 N2 Atomizer (measured) L/min 0.0 4.1 0.0 4.0 0.0 5.5 0.0 5.1 Air from the bottom (measured) L/min 4.0 2.0 4.0 2.1 3.8 1.7 3.7 2.1 N2 from the bottom (measured) L/min 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry or Bio-oil feeding rate g/min 6.47 6.40 6.42 6.42 7.90 7.90 7.90 7.90 H % in Slurry or Bio-oil % 6.48 6.48 6.48 6.48 7.22 7.22 7.22 7.22 C % in Slurry or Bio-oil % 48.39 48.39 48.39 48.39 42.47 42.47 42.47 42.47 N % in Slurry or Bio-oil % 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 O % in Slurry or Bio-oil % 43.37 43.37 43.37 43.37 49.71 49.71 49.71 49.71 Water content of Slurry or Bio-oil %-wt 20.00 20.00 20.00 20.00 25.22 25.22 25.22 25.22 Product Gas Temperature (T at flow meter) (°C) 28.5 30.1 28.9 29.9 26.5 27.2 27.2 26.3 Product gas Flow rate (measured) L/min in N2 20.18 21.20 21.24 21.46 24.72 24.12 23.62 21.52 Pressure at Flow meter kPa-g 3.38 3.47 2.41 2.43 2.75 2.70 2.84 2.12 H2 in Product gas (N2 included) % 15.42 22.02 12.96 18.90 23.01 24.39 17.82 21.12 N2 in Product gas (N2 included) % 58.88 52.53 61.47 56.62 50.33 50.72 55.38 54.29 CO in Product gas (N2 included) % 3.19 6.89 2.98 4.67 4.89 6.43 4.65 5.47 CH4 in Product gas (N2 included) % 0.38 0.83 0.55 1.03 0.00 0.98 0.49 1.01 CO2 in Product gas (N2 included) % 19.42 15.27 19.06 16.09 18.78 14.77 18.53 15.46 Acetylene C2H2 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Ethylene C2H4 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.30 Ethane C2H6 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.07 Propene C3H6 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.02 Propane C3H8 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Isobutane C4H10 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1-Butene C4H8 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.02 Butane C4H10 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1 7 4 A p p en d ix G E xp erim en ta l d a ta Table G.2 Experimental data of partial oxidation #2 Run name PO_SE15-1 PO_SE15-2 PO_SE15-3 PO_SE15-4 PO_SE15-5 PO_SE09-1 PO_SE09-2 PO_SE09-3 Feed Slurry Slurry Slurry Slurry Slurry Bio-oil Bio-oil Bio-oil Bed material Sand Sand Sand Sand Sand Sand Sand Sand Gasification temperature (Bed temperature) (°C) 847 839 744 744 843 844 843 745  air ratio - 0.5 0.3 0.5 0.3 0.5 0.5 0.3 0.5 Bed pressure kPa-g 21.8 23.3 24.6 35.1 44.4 16.3 16.3 17.7 Water feed g/min 8.80 8.93 8.67 8.63 8.64 8.47 8.10 8.25 Air Atomizer (measured) L/min 12.1 9.0 12.3 10.5 16.0 12.0 8.0 12.0 N2 Atomizer (measured) L/min 0.0 6.3 3.2 6.6 0.0 0.0 5.1 0.0 Air from the bottom (measured) L/min 4.4 2.1 4.5 2.3 4.7 4.0 2.0 4.0 N2 from the bottom (measured) L/min 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry or Bio-oil feeding rate g/min 6.39 6.39 6.39 6.39 6.39 7.80 7.80 7.80 H % in Slurry or Bio-oil % 6.48 6.48 6.48 6.48 6.48 7.22 7.22 7.22 C % in Slurry or Bio-oil % 48.39 48.39 48.39 48.39 48.39 42.47 42.47 42.47 N % in Slurry or Bio-oil % 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 O % in Slurry or Bio-oil % 43.37 43.37 43.37 43.37 43.37 49.71 49.71 49.71 Water content of Slurry or Bio-oil %-wt 20.00 20.00 20.00 20.00 20.00 25.22 25.22 25.22 Product Gas Temperature (T at flow meter) (°C) 31.5 35.0 37.0 47.2 42.3 27.1 29.5 32.1 Product gas Flow rate (measured) L/min in N2 18.59 22.05 22.95 25.16 22.89 22.06 22.57 23.24 Pressure at Flow meter kPa-g 5.23 5.55 5.53 6.26 6.54 2.09 2.15 2.35 H2 in Product gas (N2 included) % 6.60 8.02 5.58 7.01 6.78 8.95 10.28 6.82 N2 in Product gas (N2 included) % 68.08 67.40 68.33 70.46 67.05 59.34 59.69 61.21 CO in Product gas (N2 included) % 7.02 10.29 8.16 8.22 7.71 11.36 12.78 14.37 CH4 in Product gas (N2 included) % 1.36 1.91 1.18 1.76 1.12 1.75 2.60 1.76 CO2 in Product gas (N2 included) % 15.60 9.47 14.57 10.39 14.93 13.37 9.17 11.01 Acetylene C2H2 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Ethylene C2H4 in Product gas (N2 included) % 0.28 0.48 0.25 0.55 0.23 0.28 0.63 0.41 Ethane C2H6 in Product gas (N2 included) % 0.00 0.01 0.00 0.06 0.00 0.00 0.02 0.01 Propene C3H6 in Product gas (N2 included) % 0.01 0.01 0.01 0.04 0.01 0.00 0.01 0.01 Propane C3H8 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Isobutane C4H10 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1-Butene C4H8 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Butane C4H10 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1 7 5 A p p en d ix G E xp erim en ta l d a ta Table G.3 Experimental data of partial oxidation #3 Run name PO_SE09-4 PO_SE09-5 PO_SE09-6 PO_NO26-1 PO_NO26-2 PO_DE02-1 PO_DE02-2 PO_SE02-1 Feed Bio-oil Bio-oil Bio-oil Slurry Bio-oil Bio-oil Slurry Bio-oil Bed material Sand Sand Sand Sand Sand Catalyst Catalyst Catalyst Gasification temperature (Bed temperature) (°C) 744 843 841 814 790 790 818 847  air ratio - 0.3 0.5 0.5 0.1 0.1 0.1 0.1 0.5 Bed pressure kPa-g 15.6 16.4 140.6 38.7 26.2 31.6 49.8 20.7 Water feed g/min 8.14 8.51 8.75 8.46 9.56 7.96 8.69 8.12 Air Atomizer (measured) L/min 8.0 12.0 14.3 1.7 1.6 1.7 1.6 12.2 N2 Atomizer (measured) L/min 5.1 0.0 0.0 11.9 12.0 12.5 12.7 0.0 Air from the bottom (measured) L/min 2.0 4.0 4.1 1.7 1.7 1.6 1.8 3.8 N2 from the bottom (measured) L/min 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry or Bio-oil feeding rate g/min 7.80 7.80 7.70 6.50 7.98 8.07 6.48 7.80 H % in Slurry or Bio-oil % 7.22 7.22 7.22 6.48 7.22 7.22 6.48 7.22 C % in Slurry or Bio-oil % 42.47 42.47 42.47 48.39 42.47 42.47 48.39 42.47 N % in Slurry or Bio-oil % 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 O % in Slurry or Bio-oil % 49.71 49.71 49.71 43.37 49.71 49.71 43.37 49.71 Water content of Slurry or Bio-oil %-wt 25.22 25.22 25.22 20.18 25.22 25.22 20.18 25.00 Product Gas Temperature (T at flow meter) (°C) 29.4 27.4 25.2 39.7 30.0 27.7 27.2 26.1 Product gas Flow rate (measured) L/min in N2 20.05 21.06 19.56 25.64 21.85 27.69 24.83 22.40 Pressure at Flow meter kPa-g 2.12 2.35 2.00 3.61 2.92 4.30 2.74 2.21 H2 in Product gas (N2 included) % 6.70 7.99 8.89 9.10 8.93 27.99 22.37 16.51 N2 in Product gas (N2 included) % 64.90 60.20 58.71 71.61 67.90 48.91 57.59 55.32 CO in Product gas (N2 included) % 13.48 11.50 11.91 8.43 11.40 10.11 6.92 6.02 CH4 in Product gas (N2 included) % 2.44 1.74 1.89 2.60 3.45 0.43 0.96 1.42 CO2 in Product gas (N2 included) % 7.67 12.92 12.95 5.71 5.26 10.17 10.18 18.03 Acetylene C2H2 in Product gas (N2 included) % 0.16 0.00 0.00 0.02 0.13 0.00 0.00 0.00 Ethylene C2H4 in Product gas (N2 included) % 0.82 0.42 0.42 0.58 0.83 0.00 0.13 0.05 Ethane C2H6 in Product gas (N2 included) % 0.09 0.01 0.00 0.04 0.06 0.00 0.01 0.01 Propene C3H6 in Product gas (N2 included) % 0.06 0.01 0.01 0.02 0.04 0.00 0.00 0.00 Propane C3H8 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Isobutane C4H10 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1-Butene C4H8 in Product gas (N2 included) % 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Butane C4H10 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1 7 6 A p p en d ix G E xp erim en ta l d a ta Table G.4 Experimental data of steam gasification #1 Run name SG_OC22-1 SG_OC22-2 SG_OC28-1 SG_OC28-2 SG_NO26-3 SG_NO26-4 Feed Slurry Bio-oil Slurry Bio-oil Bio-oil Bio-oil Bed material Catalyst Catalyst Sand Sand Sand Sand Gasification temperature (Bed temperature) (°C) 815 803 836 832 806 808  air ratio - 0 0 0 0 0 0 Bed pressure kPa-g 21.4 46.6 34.5 25.6 16.3 19.2 Water feed g/min 13.27 13.03 13.84 14.29 6.20 19.43 Air Atomizer (measured) L/min 0.0 0.0 0.0 0.0 0.0 0.0 N2 Atomizer (measured) L/min 12.5 12.0 12.3 12.3 12.4 12.6 Air from the bottom (measured) L/min 0.0 0.0 0.0 0.0 0.0 0.0 N2 from the bottom (measured) L/min 0.0 0.0 0.0 0.0 0.0 0.0 Slurry or Bio-oil feeding rate g/min 3.35 4.27 3.44 4.20 4.26 4.32 H % in Slurry or Bio-oil % 6.48 7.22 6.48 7.22 7.22 7.22 C % in Slurry or Bio-oil % 48.39 42.47 48.39 42.47 42.47 42.47 N % in Slurry or Bio-oil % 0.30 0.30 0.30 0.30 0.30 0.30 O % in Slurry or Bio-oil % 43.37 49.71 43.37 49.71 49.71 49.71 Water content of Slurry or Bio-oil %-wt 20.18 25.22 20.18 25.22 25.22 25.22 Product Gas Temperature (T at flow meter) (°C) 29.3 29.0 38.5 26.5 28.3 31.0 Product gas Flow rate (measured) L/min in N2 18.50 18.99 14.97 15.07 15.62 17.38 Pressure at Flow meter kPa-g 2.50 3.50 2.77 2.83 3.20 3.33 H2 in Product gas (N2 included) % 21.70 23.72 8.58 8.52 8.05 7.82 N2 in Product gas (N2 included) % 63.29 58.68 78.08 75.84 76.23 76.07 CO in Product gas (N2 included) % 2.93 4.30 6.07 7.98 7.83 8.17 CH4 in Product gas (N2 included) % 0.42 1.20 2.15 2.69 2.66 2.65 CO2 in Product gas (N2 included) % 9.08 9.92 3.49 3.14 2.90 2.65 Acetylene C2H2 in Product gas (N2 included) % 0.00 0.00 0.00 0.10 0.05 0.10 Ethylene C2H4 in Product gas (N2 included) % 0.00 0.18 0.48 0.69 0.63 0.65 Ethane C2H6 in Product gas (N2 included) % 0.00 0.01 0.02 0.04 0.03 0.04 Propene C3H6 in Product gas (N2 included) % 0.00 0.01 0.02 0.03 0.02 0.04 Propane C3H8 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 Isobutane C4H10 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 1-Butene C4H8 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 Butane C4H10 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 1 7 7 A p p en d ix G E xp erim en ta l d a ta Table G.5 Experimental data of steam gasification #2 Run name SG_NO30-1 SG_NO30-2 SG_NO30-3 SG_NO30-4 SG_DE02-3 SG_DE04-1 SG_DE04-2 SG_DE04-3 Feed Bio-oil Bio-oil Bio-oil Bio-oil Slurry Bio-oil Bio-oil Slurry Bed material Sand Sand Sand Sand Catalyst Catalyst Catalyst Catalyst Gasification temperature (Bed temperature) (°C) 800 790 780 747 784 773 725 755  air ratio - 0 0 0 0 0 0 0 0 Bed pressure kPa-g 17.2 18.4 19.9 16.9 57.5 24.8 35.9 50.7 Water feed g/min 9.40 13.46 17.04 13.13 13.10 13.80 12.80 12.93 Air Atomizer (measured) L/min 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 N2 Atomizer (measured) L/min 12.5 12.5 12.5 12.8 12.0 13.0 13.0 13.0 Air from the bottom (measured) L/min 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 N2 from the bottom (measured) L/min 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Slurry or Bio-oil feeding rate g/min 2.71 4.18 5.34 4.27 3.49 4.24 4.22 3.46 H % in Slurry or Bio-oil % 7.22 7.22 7.22 7.22 6.48 7.22 7.22 6.48 C % in Slurry or Bio-oil % 42.47 42.47 42.47 42.47 48.39 42.47 42.47 48.39 N % in Slurry or Bio-oil % 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 O % in Slurry or Bio-oil % 49.71 49.71 49.71 49.71 43.37 49.71 49.71 43.37 Water content of Slurry or Bio-oil %-wt 25.22 25.22 25.22 25.22 20.18 25.22 25.22 20.18 Product Gas Temperature (T at flow meter) (°C) 30.6 29.3 31.0 29.8 28.6 27.3 23.5 25.7 Product gas Flow rate (measured) L/min in N2 16.07 16.22 17.79 15.77 16.71 21.67 20.97 17.66 Pressure at Flow meter kPa-g 3.25 3.52 3.81 3.59 7.31 2.08 2.01 2.13 H2 in Product gas (N2 included) % 4.84 6.60 6.68 4.96 20.36 26.61 25.43 19.86 N2 in Product gas (N2 included) % 85.45 80.63 77.50 83.70 64.42 55.90 58.33 66.35 CO in Product gas (N2 included) % 5.08 7.29 8.82 6.55 2.66 3.23 3.79 2.23 CH4 in Product gas (N2 included) % 1.72 2.45 3.02 2.06 0.84 0.00 0.33 0.41 CO2 in Product gas (N2 included) % 1.43 1.94 2.15 1.25 9.38 11.04 10.46 9.14 Acetylene C2H2 in Product gas (N2 included) % 0.11 0.15 0.17 0.16 0.00 0.00 0.00 0.00 Ethylene C2H4 in Product gas (N2 included) % 0.46 0.66 0.77 0.66 0.10 0.00 0.00 0.05 Ethane C2H6 in Product gas (N2 included) % 0.04 0.06 0.07 0.08 0.02 0.00 0.00 0.02 Propene C3H6 in Product gas (N2 included) % 0.03 0.05 0.07 0.08 0.01 0.00 0.01 0.01 Propane C3H8 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Isobutane C4H10 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1-Butene C4H8 in Product gas (N2 included) % 0.00 0.00 0.01 0.02 0.00 0.00 0.00 0.00 Butane C4H10 in Product gas (N2 included) % 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 178 APPENDIX H Sample Calculations A sample calculation sheet is provided here. Table H.1 Sample calculation for run ID: PO_OC14-2 Data input Run name PO_OC14- 2 Feed Slurry Bed material Catalyst Room temperature Troomc °C 25 Room temperature Troomk K =Troomc+273.15 298.15 Gasification temperature Trc °C 748 Gasification temperature Trk K =Trc+273.15 1021.15  air ratio lamda mol/mol 0.3 Bed pressure P kPa-g 73.4 Water feed Wf g/min 9.02 Air Atomizer (measured) Aatomizer L/min 8.6 N2 Atomizer (measured) N2atomizer L/min 4.0 Air from the bottom (measured) Abottom L/min 2.1 N2 from the bottom (measured) N2bottom L/min 0.0 Slurry or Bio-oil feeding rate F g/min 6.42 H % in Slurry or Bio- oil [Hfeed] % 6.48 C % in Slurry or Bio- oil [Cfeed] % 48.39 N % in Slurry or Bio- oil [Nfeed] % 0.30 O % in Slurry or Bio- oil [Ofeed] % 43.37 Water content of Slurry or Bio-oil [Wfeed] %-wt 20.00 Product Gas Temperature (T at flow meter) Tpc (°C) 29.88 Product gas Flow rate (measured) Vpmeasured L/min in N2 21.46 Pressure at Flow meter Pfm kPa-g 2.43 Appendix H Sample calculations 179 A p p en d ices H2 in Product gas (N2 included) [H2p] % 18.90 N2 in Product gas (N2 included) [N2p] % 56.62 CO in Product gas (N2 included) [COp] % 4.67 CH4 in Product gas (N2 included) [CH4p] % 1.03 CO2 in Product gas (N2 included) [CO2p] % 16.09 Acetylene C2H2 in Product gas (N2 included) [C2H2p] % 0.00 Ethylene C2H4 in Product gas (N2 included) [C2H4p] % 0.00 Ethane C2H6 in Product gas (N2 included) [C2H6p] % 0.00 Propene C3H6 in Product gas (N2 included) [C3H6p] % 0.00 Propane C3H8 in Product gas (N2 included) [C3H8p] % 0.00 Isobutane C4H10 in Product gas (N2 included) [iC4H10p] % 0.00 1-Butene C4H8 in Product gas (N2 included) [1C4H8p] % 0.00 Butane C4H10 in Product gas (N2 included) [nC4H10p] % 0.00 Catalyst or sand weight Wbed g 780 Catalyst or sand bulk density Dbed g/cm3 1.3 Bed volume Vbed cm3 =Wbed/Dbed 600 Constants Atomic weight of H AWH g/mol 1.00794 - Atomic weight of C AWC g/mol 12.0107 - Atomic weight of N AWN g/mol 14.0067 - Atomic weight of O AWO g/mol 15.9994 - Gas constant R J/mol K 8.31447 - Feed Water feed nWf mol/min =Wf/18.01528 0.50 Water in Slurry or Bio-oil mWfeed g/min =F*[Wfeed]/100 1.28 Appendix H Sample calculations 180 A p p en d ices Water in Slurry or Bio-oil nWfeed mol/min =mWfeed/18.01528 0.07 Air Atomizer (measured) nAatomizer mol/min =101300*Aatomizer/1000/(R*Troo mk) 0.36 N2 Atomizer (measured) nN2atomizer mol/min =101300*N2atomizer/1000/(R*Tro omk) 0.16 N2 Atomizer (Total) vTotN2atomizer L/min =Aatomizer*0.790524+N2atomizer 10.71 N2 Atomizer (Total) nTotN2atomizer mol/min =101300*vTotN2atomizer/1000/(R *Troomk) 0.45 O2 Atomizer (Total) vTotO2atomizer L/min =Aatomizer*0.209476 1.79 O2 Atomizer (Total) nTotO2atomizer mol/min =101300*vTotO2atomizer/1000/(R *Troomk) 0.07 Air from the bottom (measured) nAbottom mol/min =101300*Abottom/1000/(R*Troomk ) 0.09 N2 from the bottom (measured) nN2bottom mol/min =101300*N2bottom/1000/(R*Troom k) 0.00 N2 from the bottom (total) vTotN2bottom L/min =Abottom*0.790524+N2bottom 1.62 N2 from the bottom (total) nTotN2bottom mol/min =101300*vTotN2bottom/1000/(R*T roomk) 0.07 O2 from the bottom (total) vTotO2bottom L/min =Abottom*0.209476 0.43 O2 from the bottom (total) nTotO2bottom mol/min =101300*vTotO2bottom/1000/(R*T roomk) 0.02 N2 in feed vN2feed L/min =vTotN2atomizer+vTotN2bottom 12.33 N2 in feed nN2feed mol/min =nTotN2atomizer+nTotN2bottom 0.51 O2 in feed vO2feed L/min =vTotO2atomizer+vTotO2bottom 2.22 O2 in feed (molecule) nO2feed mol/min =nTotO2atomizer+nTotO2bottom 0.09 Total gas nTotfeed mol/min =nWf+nN2feed+nO2feed 1.11 H in Slurry or Bio-oil mHfeed g/min =F*[Hfeed]/100 0.416 C in Slurry or Bio-oil mCfeed g/min =F*[Cfeed]/100 3.107 N in Slurry or Bio-oil mNfeed g/min =F*[Nfeed]/100 0.019 O in Slurry or Bio-oil mOfeed g/min =F*[Ofeed]/100 2.785 H in Slurry or Bio-oil nHfeed mol/min =mHfeed/AWH 0.413 C in Slurry or Bio-oil nCfeed mol/min =mCfeed/AWC 0.259 N in Slurry or Bio-oil nNfeed mol/min =mNfeed/AWN 0.001 O in Slurry or Bio-oil nOfeed mol/min =mOfeed/AWO 0.174 H in Slurry or Bio-oil (Dry) mHfeeddry g/min =F*[Hfeed]/100- F*[Wfeed]/100/(AWH*2+AWO)*2*AW H 0.272 H in Slurry or Bio-oil (Dry) nHfeeddry mol/min =mHfeeddry/AWH 0.270 Product Product Gas Temperature (T at flow meter) Tpk K =Tpc+273.15 303 Appendix H Sample calculations 181 A p p en d ices N2 Viscosity (calculated) muN2 Pa·s =0.00000065592*Tpk^0.6081/(1+5 4.714/Tpk+0/Tpk^2) 1.79E-05 Viscosity (calculated) muproduct Pa·s Viscosity of mixed gas was calculated by correlation below, mix=i=1 n (xii/j=1 n xjij) ij=8 -1/2 (1+Mi/Mj) -1/2 ·[1+(i/j) 1/2 (Mj/Mi) 1/4 ] 2 xi: mole fraction of i species i: viscotisy of i species Mi: molecular weight of i species 1.71E-05 Product gas Flow rate (calculated) Vpcompensated L/min =Vpmeasured*muN2/muproduct 22.45 H2 in Product gas (N2 included) VH2p L/min =Vpcompensated*[H2p]/100 4.24 N2 in Product gas (N2 included) VN2p L/min =Vpcompensated*[N2p]/100 12.71 CO in Product gas (N2 included) VCOp L/min =Vpcompensated*[COp]/100 1.05 CH4 in Product gas (N2 included) VCH4p L/min =Vpcompensated*[CH4p]/100 0.23 CO2 in Product gas (N2 included) VCO2p L/min =Vpcompensated*[CO2p]/100 3.61 Acetylene C2H2 in Product gas (N2 included) VC2H2p L/min =Vpcompensated*[C2H2p]/100 0.00 Ethylene C2H4 in Product gas (N2 included) VC2H4p L/min =Vpcompensated*[C2H4p]/100 0.00 Ethane C2H6 in Product gas (N2 included) VC2H6p L/min =Vpcompensated*[C2H6p]/100 0.00 Propene C3H6 in Product gas (N2 included) VC3H6p L/min =Vpcompensated*[C3H6p]/100 0.00 Propane C3H8 in Product gas (N2 included) VC3H8p L/min =Vpcompensated*[C3H8p]/100 0.00 Isobutane C4H10 in Product gas (N2 included) ViC4H10p L/min =Vpcompensated*[iC4H10p]/100 0.00 1-Butene C4H8 in Product gas (N2 included) V1C4H8p L/min =Vpcompensated*[1C4H8p]/100 0.00 Butane C4H10 in Product gas (N2 included) VnC4H10p L/min =Vpcompensated*[nC4H10p]/100 0.00 H2 in Product gas (N2 included) nH2p mol/min =(101300+pfm*1000)*VH2p/1000/( R*Tpk) 0.17 N2 in Product gas (N2 included) nN2p mol/min =(101300+pfm*1000)*VN2p/1000/( R*Tpk) 0.52 CO in Product gas (N2 included) nCOp mol/min =(101300+pfm*1000)*VCOp/1000/( R*Tpk) 0.04 CH4 in Product gas (N2 included) nCH4p mol/min =(101300+pfm*1000)*VCH4p/1000/ (R*Tpk) 0.01 Appendix H Sample calculations 182 A p p en d ices CO2 in Product gas (N2 included) nCO2p mol/min =(101300+pfm*1000)*VCO2p/1000/ (R*Tpk) 0.15 Acetylene C2H2 in Product gas (N2 included) nC2H2p mol/min =(101300+pfm*1000)*VC2H2p/1000 /(R*Tpk) 0.00 Ethylene C2H4 in Product gas (N2 included) nC2H4p mol/min =(101300+pfm*1000)*VC2H4p/1000 /(R*Tpk) 0.00 Ethane C2H6 in Product gas (N2 included) nC2H6p mol/min =(101300+pfm*1000)*VC2H6p/1000 /(R*Tpk) 0.00 Propene C3H6 in Product gas (N2 included) nC3H6p mol/min =(101300+pfm*1000)*VC3H6p/1000 /(R*Tpk) 0.00 Propane C3H8 in Product gas (N2 included) nC3H8p mol/min =(101300+pfm*1000)*VC3H8p/1000 /(R*Tpk) 0.00 Isobutane C4H10 in Product gas (N2 included) niC4H10p mol/min =(101300+pfm*1000)*ViC4H10p/10 00/(R*Tpk) 0.00 1-Butene C4H8 in Product gas (N2 included) n1C4H8p mol/min =(101300+pfm*1000)*V1C4H8p/100 0/(R*Tpk) 0.00 Butane C4H10 in Product gas (N2 included) nnC4H10p mol/min =(101300+pfm*1000)*VnC4H10p/10 00/(R*Tpk) 0.00 H in Product gas (N2 included) mHp g/min =(nH2p*2+nCH4p*4+nC2H2p*2+nC2H 4p*4+nC2H6p*6+nC3H6p*6+nC3H8p* 8+niC4H10p*10+n1C4H8p*8+nnC4H1 0p*10)*AWH 0.39 C in Product gas (N2 included) mCp g/min =(nCOp+nCH4p+nCO2p+(nC2H2p+nC2 H4p+nC2H6p)*2+(nC3H6p+nC3H8p)* 3+(niC4H10p+n1C4H8p+nnC4H10p)* 4)*AWC 2.42 N in Product gas (N2 included) mNp g/min =nN2p*2*AWN 14.66 O in Product gas (N2 included) mOp g/min =(nCOp+nCO2p*2)*AWO 5.45 Stoichiometric H2 (molecule) nStoicH2 mol/min =2*nCfeed+0.5*nHfeed-nOfeed 0.55 Summary  (Actual) Lamdaactual mol/mol =nO2feed*2/(0.5*nHfeed+2*nCfee d-nOfeed) 0.34 H2O/C (Actual) StoCactual mol/mol =(nWf+nWfeed)/nCfeed 2.21 GC1HSV (Actual) GC1HSVactual m3/m3 =nCfeed*R*273.15/101300*1000*6 0/VBed*1000 518 Bed pressure Pabs kPa-abs =101.3+P 175 Feeding rate in g/ml- cat FperVbed g/ml-cat =F/Vbed 0.010 Steam in feed [Steaminfeed] %-mol =nWf/nTotfeed*100 45 N2 in feed [N2infeed] %-mol =nN2feed/nTotfeed*100 46 Appendix H Sample calculations 183 A p p en d ices O2 in feed [O2infeed] %-mol =nO2feed/nTotfeed*100 8 O from steam and air (Product gas) YOfromsteamair % =(mOp-mOfeed)/mOp*100 49 H from steam (Product gas) YHfrom steam % =(mHp-mHfeed)/mHp*100 -6 C conversion (Carbon to gas) Cconv % =mCp/mCfeed*100 78 H2 yield (stoichiometric) YH2stoic %-mol =nH2p/nStoicH2*100 32 H2 yield from 1 kg feed YH2perkgfeed kg/kg =nH2p*AWH*2/F 0.055 H2/CO in product gas H2toCO mol/mol =nH2p/nCOp 4.0 N2 closure N2clos %-vol =VN2p/vN2feed*100 103 H2 in Product gas (N2 free) [H2pN2free] % =[H2p]/(100-[N2p])*100 43.6 CO in Product gas (N2 free) [COpN2free] % =[N2p]/(100-[N2p])*100 10.8 CH4 in Product gas (N2 free) [CH4pN2free] % =[CH4p]/(100-[N2p])*100 2.4 CO2 in Product gas (N2 free) [CO2pN2free] % =[CO2p]/(100-[N2p])*100 37.1 Acetylene C2H2 in Product gas (N2 free) [C2H2pN2free] % =[C2H2p]/(100-[N2p])*100 0.0 Ethylene C2H4 in Product gas (N2 free) [C2H4pN2free] % =[C2H4p]/(100-[N2p])*100 0.0 Ethane C2H6 in Product gas (N2 free) [C2H6pN2free] % =[C2H6p]/(100-[N2p])*100 0.0 Propene C3H6 in Product gas (N2 free) [C3H6pN2free] % =[C3H6p]/(100-[N2p])*100 0.0 Propane C3H8 in Product gas (N2 free) [C3H8pN2free] % =[C3H8p]/(100-[N2p])*100 0.0 Isobutane C4H10 in Product gas (N2 free) [iC4H10pN2free] % =[iC4H10p]/(100-[N2p])*100 0.0 1-Butene C4H8 in Product gas (N2 free) [1C4H8pN2free] % =[1C4H8p]/(100-[N2p])*100 0.0 Butane C4H10 in Product gas (N2 free) [nC4H10pN2free] % =[nC4H10p]/(100-[N2p])*100 0.0 Carbon yield as CO YCasCO %mol/mol feed =nCOp/nCfeed*100 16.7 Carbon yield as CO2 YCasCO2 %mol/mol feed =nCO2p/nCfeed*100 57.5 Carbon yield as CH4 YCasCH4 %mol/mol feed =nCH4p/nCfeed*100 3.7 Carbon yield as C2- C4 YCasC2to4 %mol/mol feed =((nC2H2p+nC2H4p+nC2H6p)*2+(nC 3H6p+nC3H8p)*3+(niC4H10p+n1C4H 8p+nnC4H10p)*4)/nCfeed*100 0.0 Hydrogen yield as H2 (Based on dry feed) YHasH2dry %mol/mol dry feed =nH2p*2/nHfeeddry*100 129.4 Hydrogen yield as CH4 (Based on dry feed) YHasCH4dry %mol/mol dry feed =nCH4p*4/nHfeeddry*100 14.1 Appendix H Sample calculations 184 A p p en d ices Hydrogen yield as C2-C4 (Based on dry feed) YHasC2to4dry %mol/mol dry feed =(nC2H2p*2+nC2H4p*4+nC2H6p*6+n C3H6p*6+nC3H8p*8+niC4H10p*10+n 1C4H8p*8+nnC4H10p*10)/nHfeeddr y*100 0.0 Steam conversion % dry feed base =(mHp- mHfeeddry)/((Wf+mWfeed)*2*AWH/ (2*AWH+AWO))*100 10.3 Superficial velocity of steam at 700C m/s =nWf*R*Trk/100000/(0.0779^2/4* PI())/60 0.149 185 APPENDIX I Heat of Reactions of Steam Gasification, Steam Gasification Followed by the Water-Gas Shift Reaction, and Partial Oxidation of Bio-Oil I.1 Heat of reaction: steam gasification, steam gasification followed by the water-gas shift reaction and partial oxidation of bio-oil Combustion of bio-oil, CH1.31O0.47 + 1.0925 O2 → CO2 + 0.655 H2O (g) H 0 298 = -462 kJ/(mol-carbon) (I.1) Combustion of hydrogen, H2 + 0.5 O2 → H2O (g) H 0 298 = -242 kJ/mol (I.2) Combustion of carbon mono oxide, CO + 0.5 O2 → CO2 H 0 298 = -283 kJ/mol (I.3) Steam gasification of bio-oil, steam gasification of bio-oil followed by water-gas-shift reaction and partial oxidation gasification of bio-oil can be described by linear combination of reactions (I-1-3). Subsequently, the heat of reactions can be obtained as followings, Steam gasification of bio-oil, CH1.31O0.47 + 0.53H2O (g) → CO + 1.185H2 = (I-1) - 1.185(I-2) - (I-3) (I.4) Appendix I Heat of reactions of steam gasification, steam gasification followed by the water-gas shift reaction, and partial oxidation of bio-oil Sample calculations 186 A p p en d ices H0298 = (-462) -1.185(-242)-(-283) = +108 kJ/(mol-carbon) Steam gasification of bio-oil followed by water-gas-shift reaction, CH1.31O0.47 + 1.53H2O (g) → CO2 + 2.185H2 = (I-1) - 2.185(I-2) H0298 = (-462) -2.185(-242) = +67 kJ/(mol-carbon) (I.5) Partial oxidation gasification of bio-oil, CH1.31O0.47 + 0.265O2 → CO + 0.655H2 = (I-1) - 0.655(I-2) - (I-3) H0298 = (-462) -0.655(-242)-(-283) = -20 kJ/(mol-carbon) (I.6) Heat of combustion of bio-oil is calculated based on, HHV = 0.341 C + 1.322 H - 0.12 (O + N) - 0.0153 A + 0.0686 S kJ/g (I.7) where C, H, O, N, S, and A are the weight percents of carbon, hydrogen, oxygen, nitrogen, sulfur, and ash respectively. N, S, and A are regarded as negligible (Domalski et al., 1987). I.2 Reference Domalski, E. S., Jobe, T. L., Jr. and Milne, T. A. (1987) Thermodynamic data for biomass materials and waste components / sponsored by the ASME research committee on industrial and municipal wastes. American Society of Mechanical Engineers, New York. 187 APPENDIX J Matlab Code for Thermodynamic Equilibrium Calculation J.1 Main program for free energy minimization (FEM) model RAND algorithm The program code originates from Li, X. (2002). It was modified for the present study as in the following: ■ Empirical equations in the original code to estimate unconverted carbon and methane concentration were deleted. For the present study, the code was modified to input unconverted carbon and yield of hydrocarbons as a kinetically modified model (J1). ■ To calculate the initial elemental abundunce from bio-oil/char slurry with different char content, the code was modified in order to input char concentration (J1 and J3). ■ S/C ratio to be input in molar ratio. File name: sdgas.m Function: Main program of equilibrium model ---------------------------------------------------------------------- disp(' EQUILIBRIUM MODEL FOR SAWDUST GASIFICATION ') disp(' - NON-STOICHIOMETRIC FREE ENERGY MINIMIZATION METHOD') % Version 1.0 [ Standard Version for C-H-O-N-S Systems ] % (C) Masakazu Sakaguchi (Jan 3, 2010) modified Xiantian Li's code % (1) Input Model Parameters % Bio-oil and slurry gasification share the same database: coaldat.m % All calculations are made based on 1 kg of feedstock (dry basis) prompt = {'Enter minimum temperature, deg C','Enter number of T intervals', 'Enter T increment, K','Enter system pressure, bar', 'Enter initial Oxygen ratio, stoichiometric','Enter Ca/S molar ratio', 'Enter fuel type index (1:Bio-oil WL)','Enter number of air ratio changes','H2O/C, mol/mol','Char content, wt%','Feeding water temperature (C)','Nitrogen purge (L/min)','Fuel feeding rate (g/min)','Kinetic modification? (y=1,n=0)','Carbon conversion (%)','C yield as hydrocarbons (%)','H yield as hydrocarbons (%-dry basis)'}; defAns = {'850', '1', '50', '1.013', '0', '0', '1', '1', '2.1', '0','20','0','6.59','0','100','100','100'} title = 'Inputs for equilibrium model' lineNo = 1; answer = inputdlg(prompt, title, lineNo, defAns); [S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, S16, S17] = deal(answer{:}); Ti = str2num(S1); % Munimum operating temperature (C) Appendix J Matlab code for thermodynamic equilibrium calculation 188 A p p en d ices T0 = Ti + 273; % Operating temperature (K) NT = str2num(S2); % Number of T intervals (-) DT = str2num(S3); % Temperature increment (K) p = str2num(S4); % System pressure (bar) alpha = str2num(S5); % Initial air ratio (-) Ca = str2num(S6); % Ca/S molar ratio (-) NF = str2num(S7); % Fuel type: 1 = Bio-oil; 2 = Char, etc. IZ = str2num(S8); % Number of outer-layer iteration times rH2O = str2num(S9); % H2O/C (mol/mol) Charcont= str2num(S10)/100; % Char content (wt. fraction kg/kg) tstm= str2num(S11); % Feeding water temperature (C) N2purge= str2num(S12); %N2 purge (L/min) feedrate= str2num(S13); %Fuel feeding rate (g/min) NFIT= str2num(S14); %0: 100% C conversion, 1: Kinetic modification TotalCyield = str2num(S15); %C conversion in % YChydroc = str2num(S16); %C yield as hydrocarbons in % YHhydroc = str2num(S17); %H yield as hydrocarbons in %% The total weight (kg) of moisture added to 1 kg of dry-basis sawdust: dalfa = 0.05; % The increment of air ratio rfuel = 1; % Fuel feed rate (kg/hr): bio-oil incl.H2O NREV = 1; % EA0: 0 = Direct input, 1 = From database NE = 5; % Number of elements NANA = 2; % Base, fuel analysis: 1: ar, 2: ad, 3: daf NO = 1; % Oxidant: 1 = air, 2 = pure oxygen NREP = 3; % Print: 1 = short, 2 = 6 species, 3 = long dissip = 0; % Dissipation from the reactor surface err = 0.00000001; % Maximum erro for convergence test NCP = 1; % Calculate fuel Cp(T) and enthalpy using: 1 = Coimbra and Queiroz (1995); 2 = Richardson (1993) Iguess = 0; % 0: simple method, 1: linear programming %-------------------------------------------------------- [Dat1, Dat11, Dat2, Dat3, Dath, Dath1] = coaldat(NE); disp(' ') disp([' Current Date: ' date ' ' ]) disp(' ') %previous_flops = flops; % (2) Calculate number of independent reactions in the system SEM = Dat2(:, [2:(1+NE)]); % Load speacies-element matrix (SEM) [N,M] = size(SEM); %Size of species-element matrix NC = M; % Number of components nr = rank(SEM); % Rank of SEM mr = N - rank(SEM); % Model parameter T = T0; % Initial temperature (K) R = 8.31448; % Thermodynamic constant, J/mol-K for i=1:N SI(i)=Dat1(i,2); % Si = State info end % Count the respective numbers of gas, liquid and solid species ngas = 0; % Initialization nliq = 0; Appendix J Matlab code for thermodynamic equilibrium calculation 189 A p p en d ices nsol = 0; for i = 1:N if SI(i) == 1 ngas = ngas + 1; elseif SI(i) == 2 nliq = nliq + 1; elseif SI(i) == 3 nsol = nsol + 1; end end % Count the number of phases NP = 1; % Gas phase as an ideal solution if nliq >= 1 NP = NP + 1; % Liquid species from another ideal solution end NP = NP + nsol; % Each solid species is an individual phase NZ = 0; % Numver of inert species N1 = N - NZ; % Numver of reactive species N2 = M + 1; % An index that will be used later N3 = M + NP; % An index that will be used later disp(' ') disp([' Number of elements considered = ' num2str(M) ]) disp([' Number of species considered = ' num2str(N) ]) disp([' Number of gaseous species = ' num2str(ngas) ]) disp([' Number of liquid species = ' num2str(nliq) ]) disp([' Number of solid species = ' num2str(nsol) ]) disp([' Number of components = ' num2str(NC) ]) disp([' Number of phases involved = ' num2str(NP) ]) disp(' ') % (3) Calculate initial element abundance (moles) alfa = alpha; % Initialization of z if NREP == 1 report = zeros(NT,1+IZ); end % ----------Start outer-layer iteration ---------------- for iz = 1:IZ % outer-layer iteration of AR or P EA0 = zeros(M,1); % Clear memory and re-initialize EA0 alfa = alpha + (iz-1)*dalfa; % Current air ratio % Call abundsd3.m to calculate an element abundance vector (EAV): [EA0,CEA,V0,Vair,mair,Uwat,Uwatadd,Hfeed,hfuel,hN2purge,HHV,hff,Conv,Tm0,tfuel,tnitro] = abundsd(NE,Dat3,rfuel,rH2O,NF,NO,NANA,NFIT,alfa,Ca,Charcont,tstm,N2purge,feedrate,TotalCyield,YCh ydroc,YHhydroc); UC = EA0(1); UH = EA0(2); UO = EA0(3); if M >= 4 UN = EA0(4); end if M >= 5 Appendix J Matlab code for thermodynamic equilibrium calculation 190 A p p en d ices US = EA0(5); end ea0 = [UC, UH, UO]; if M == 3 mfeed = UC*12.011 + UH*1.00794 + UO*15.994; elseif M == 4 mfeed = UC*12.011 + UH*1.00794 + UO*15.994 + UN*14.0067; elseif M == 5 mfeed = UC*12.011 + UH*1.00794 + UO*15.994 + UN*14.0067 + US*32.066; end totmol = 0.0; % The total moles of all feed elements for j = 1:M totmol = totmol + EA0(j); end CEA = EA0; % (4) Estimate the initial guess of gas composition (y and x vectors) A0 = [ %Components 1 0 1 0 0 0 0 0 % CO = 14 (Species ID number) 0 2 0 0 0 0 0 0 % H2 = 11 1 0 2 0 0 0 0 0 % CO2 = 15 0 0 0 2 0 0 0 0 % N2 = 22 0 0 0 0 1 0 0 0 % S(g) = 33 0 0 0 0 0 1 0 0 % Cl(g) = 43 0 0 0 0 0 0 1 0 % Na(g) = 46 0 0 0 0 0 0 0 1 ]; % Ca(g) = 50 % (4.1) a0 is the coefficient matrix to estimate the moles of components. % Row = species; Col = element a0 = A0(1:M,1:M); if M == 3 anonc = [SEM(1:10,:); SEM(12:13,:); SEM(16:21,:)]; elseif M == 4 anonc = [SEM(1:10,:); SEM(12:13,:); SEM(16:21,:); SEM(23:32,:)]; elseif M == 5 anonc = [SEM(1:10,:); SEM(12:13,:); SEM(16:21,:); SEM(23:32,:); SEM(34:44,:)]; elseif M == 6 anonc = [SEM(1:10,:); SEM(12:13,:); SEM(16:21,:); SEM(23:32,:); SEM(34:42,:); SEM(44:47,:)]; elseif M == 7 anonc = [SEM(1:10,:); SEM(12:13,:); SEM(16:21,:); SEM(23:32,:); SEM(34:42,:); SEM(44:45,:); SEM(47:64,:)]; elseif M == 8 anonc = [SEM(1:10,:); SEM(12:13,:); SEM(16:21,:); SEM(23:32,:); SEM(34:42,:); SEM(44:45,:); SEM(47:49,:); SEM(51:77,:)]; end % -------------------------------------------------- if Iguess == 0 % (4.2) Make an initial guess by a hand-estimation device small = min(EA0); % Smallest component in EA0 stoi = [UC, UH, UO/1.5]; % A device to evaluate C-H-O stoichiometry Appendix J Matlab code for thermodynamic equilibrium calculation 191 A p p en d ices smaller = min(stoi); % smallest element in UC, UH and UO/1.5 ynonc = small * ones(N-M, 1)/10000; % This logical variable modifies the initial guess for H2O to keep all component moles positive. % The following block is valid only for M >= 3: if smaller == stoi(1) % C-lean ynonc(10) = UH - UC; % Deduce H as H(g) ynonc(11) = UO - 1.5 * UC; % Deduce O as O(g) elseif smaller == stoi(2) % H-lean ynonc(1) = UC - UH; % Deduce C as C(g) ynonc(11) = UO - 1.5 * UH; %Deduce O as O(g) elseif smaller == stoi(3) % O-lean ynonc(1) = UC - UO/1.5; % Deduce C as C(g) ynonc(10) = UH - UO/1.5; % Dedice H as H(g) end % End of the block lens = length(ynonc); if lens ~= (N-NC) disp(' Length of the non-component vector is wrong.') pause end % Calculate b0 the right-hand side vector db0 = zeros(M,1); b0 = zeros(M,1); for k = 1:M for i = 1:(N-M) db0(k) = db0(k) + anonc(i,k)*ynonc(i); end b0(k) = EA0(k) - db0(k); end % Solve for initial guess yc0 = a0\b0; % Use transpose of b0. if M == 3 y0 = [ynonc(1:10); yc0(2); ynonc(11:12); yc0(1); yc0(3); ynonc(13:18) ]; elseif M == 4 y0 = [ynonc(1:10); yc0(2); ynonc(11:12); yc0(1); yc0(3); ynonc(13:18); yc0(4); ynonc(19:29)]; elseif M == 5 y0 = [ynonc(1:10); yc0(2); ynonc(11:12); yc0(1); yc0(3); ynonc(13:18); yc0(4); ynonc(19:28); yc0(5); ynonc(29:39)]; elseif M == 6 y0 = [ynonc(1:10); yc0(2); ynonc(11:12); yc0(1); yc0(3); ynonc(13:18); yc0(4); ynonc(19:28); yc0(5); ynonc(29:37); yc0(6); ynonc(38:47)]; elseif M == 7 y0 = [ynonc(1:10); yc0(2); ynonc(11:12); yc0(1); yc0(3); ynonc(13:18); yc0(4); ynonc(19:28); yc0(5); ynonc(29:37); yc0(6); ynonc(38:41); yc0(7); ynonc(42:57)]; elseif M == 8 y0 = [ynonc(1:10); yc0(2); ynonc(11:12); yc0(1); yc0(3); ynonc(13:18); yc0(4); ynonc(19:28); yc0(5); ynonc(29:37); yc0(6); ynonc(38:41); yc0(7); ynonc(42:43); yc0(8); ynonc(44:69)]; end % [h,H] = enth(Dath,Dath1,T,y0); % Calculate enthalpy [cy0,ys0,x0,xg0,xs0,EA,CEA0] = calcc(SI, SEM, y0, EA0); Appendix J Matlab code for thermodynamic equilibrium calculation 192 A p p en d ices % (4.3) Check the non-negativity constraint ymin = min(yc0) if ymin < 0 NT = 1; NIT = 1; disp(' ') disp(' Non-negativity requirements not met.') disp(' Use linear programming to make another initial guess.') disp(' ') end end % End initial guess % (5) Update CEA and dy to serve as the basis for iteration [cy,ys,x,xg,xs,EA,CEA] = calcc(SI,SEM,y0,EA0); % (6) Solve for a new set of y(i) by iteration using RAND algorithm m = 1; % Mark the first iteration Ind = 0; % If Ind = 0, go ahead to next iteration. % The following sentences are for initialization a1 = zeros(N3, N3) + eps; y = y0; summit = zeros(NT,1); xt = zeros(NT,N); yt = zeros(NT,N); xtdry = zeros(NT,N); dqt = zeros(NT,1); Cwat = zeros(NT,1); hhvgas = zeros(NT,1); HHVgas = zeros(NT,1); hhvdry = zeros(NT,1); vgdry = zeros(NT,1); vgwet = zeros(NT,1); E1 = zeros(NT,1); E2 = zeros(NT,1); spc = zeros(NT,2); sph = zeros(NT,2); spo = zeros(NT,2); spn = zeros(NT,2); sps = zeros(NT,2); gama = zeros(NT,1); mathane = zeros(NT,1); % End of matrix initialization. if NREP ~= 1 report = [ ]; report1 = [ ]; report2 = [ ]; end % (6.1) Start temperature iteration for it = 1:NT % Starts temperature iteration if it == 1 NIT = 100; else NIT = 40; %Maximum number of iterations for i = 1:N y(i) = yt(it-1,i); end end TT(it) = T0 + (it-1)*DT; T = TT(it); Appendix J Matlab code for thermodynamic equilibrium calculation 193 A p p en d ices % Initialization for each T iteration: [cy,ys,x,xg,xs,EA,CEA] = calcc(SI,SEM,y,EA0); [smu,smustar] = mut(T,p,Dat1,Dat11); [h,H] = enth(Dath,Dath1,T,y); % End of initialization. % Calculate chemical potential of each species for i = 1:N if SI(i) == 1 smutp(i) = smustar(i) + R*T*log(xg(i)+1e-200)/1000.0; % Gases elseif SI(i) == 2 smutp(i) = smustar(i); % Liquids elseif SI(i) == 3 smutp(i) = smustar(i); % Solids end end % Calculate the total enthalpy and total free energy toth = 0.0; totg = 0.0; for i = 1:N toth = toth + H(i); % Total enthalpy of reaction system totg = totg + smutp(i); %Total Gibbs free energy of system end Ind = 0; % Continue iteration until a new value is given to Ind. while Ind == 0 % (7) Calculate the chemical potential of species i at T and p. itm = mod(it,30); imm = mod(m,30); [a1,b1,ra1,ra2] = abzuc(SI,SEM,EA,CEA,EA0,smutp,T,p,y,imm); x1 = a1\b1; % (7.1) Calculate new species mole numbers. bir = zeros(N,1); f = zeros(N,1); dy = zeros(N,1); % Calculate dy(i) for i = 1:N for j = 1:M % Important intermediate argument. bir(i) = bir(i) + SEM(i,j) * x1(j); % Do not alter anything in this line. end Appendix J Matlab code for thermodynamic equilibrium calculation 194 A p p en d ices if SI(i) == 1 f(i) = bir(i) + x1(N2) - smutp(i)*1000/(R*T); end if M == 3 f(21) = x1(N2+1); % C(s) elseif M == 4 f(33) = x1(N2+1); % C(s) elseif M == 5 f(43) = x1(N2+1); % C(s) f(44) = x1(N2+2); % S(s) elseif M == 6 f(46) = x1(N2+1); % C(s) f(47) = x1(N2+2); % S(s) end % Add other single-species phases HERE in future versions. end for i = 1:N dy(i) = f(i)*y(i); % Increase in each species moles end [ynew] = forcer(dy,y); % Call the convergence forcer y = ynew; maxdy = max(abs(dy)); % (7.2) Update system data, prepare for next temperature iteration. [cy,ys,x,xg,xs,EA,CEA] = calcc(SI,SEM,y,EA0); [dq,totdh,totdgh,toth,totph,totgh,totsh] = heatcoal(T,alfa,Dath,Dat2,Dat3,NF,H,y,Uwat,Ca,dissip,Hfeed,hff,tstm); dqt(it) = dq; totdht(it) = totdh; totht(it) = toth; totpht(it) = totph; totght(it) = totgh; totsht(it) = totsh; Ttoth(it) = toth; % disp([' Net heat output to maintain current T = ' num2str(dq) ' kJ/hr' ]) for i = 1:N if SI(i) == 1 smutp(i) = smustar(i) + R*T*log(xg(i)+1e-200)/1000.0; elseif SI(i) == 3 smutp(i) = smustar(i); end end % (7.3) Calculate the species split of each element for i = 1:N Cy(it,i) = cy(i,1); Hy(it,i) = cy(i,2); Oy(it,i) = cy(i,3); if M >= 4 Ny(it,i) = cy(i,4); end end Appendix J Matlab code for thermodynamic equilibrium calculation 195 A p p en d ices % (7.4) Set condition for termination of iteration if m > NIT Ind = 2; elseif max(abs(dy)) <= err % Never write it as: abs(max(dy)) !! Ind = 1; else Ind = 0; end m= m + 1; end % Terminate temperature iteration (while end) % Record the Ind value if itm == 1 if Ind == 1 disp(' ') disp([' Convergence is attained at the ' num2str(m) '-th iteration.']) disp(' ') elseif Ind == 2 disp([' Convergence not attained after ' num2str(NIT) ' iteration.']) end end Ind = 0; % Reset Ind. Very impotant sentence. m = 1; % Reset m. for i = 1:N yt(it,i) = y(i); xt(it,i) = x(i); xtg(it,i) = xg(i); dqt(it) = dq; end for i = 1:N xtdry(it,i) = xtg(it,i)/(1 - xtg(it,17)); % Species content in dry gas summit(it) = summit(it) + yt(it,i); end % (7.5) Calculate equilibrium composition to be reported if M == 5 % This function designed for sawdust for i = 1:N % Overall molar composition xt(it,i) = yt(it,i)/summit(it); % Wet gas composition, excluding C(s) and S(s) xtg(it,i) = yt(it,i)/(summit(it) - yt(it,43) - yt(it,44)); % Dry gas composition, excluding water, C(s) and S(s) xtdry(it,i) = yt(it,i)/(summit(it) - yt(it,17) - yt(it,43) - yt(it,44)); % N2 free dry gas composition, excluding Nitrogen, water, C(s) and S(s) xtdryNN(it,i) = yt(it,i)/(summit(it) - yt(it,17)- yt(it,22) - yt(it,43) - yt(it,44)); end xtg(it,43) = 0; xtg(it,44) = 0; xtdry(it,17) = 0; Appendix J Matlab code for thermodynamic equilibrium calculation 196 A p p en d ices xtdry(it,43) = 0; xtdry(it,44) = 0; xtdryNN(it,17)= 0; xtdryNN(it,22)= 0; xtdryNN(it,43)= 0; xtdryNN(it,44)= 0; end % Water conversion Cwat(it) = 100 * (Uwat - yt(it,17)) / Uwat; % Units in (%) % Calculate wet gas HHV: if M <= 4 hhvgas(it) = 100/(8.31448*298.15)* ( xtg(it,5)*890.8 + xtg(it,6)*1301.1 + xtg(it,7)*1411.2 + xtg(it,8)*1560.7 + xtg(it,9)*2220.1 + xtg(it,11)*285.8 + xtg(it,14)*283.0 ); % MJ/NM3 elseif M >= 5 hhvgas(it) = 100/(8.31448*298.15)* ( xtg(it,5)*890.8 + xtg(it,6)*1301.1 + xtg(it,7)*1411.2 + xtg(it,8)*1560.7 + xtg(it,9)*2220.1 + xtg(it,11)*285.8 + xtg(it,14)*283.0 + xtg(it,42)*562.6 + xtg(it,38)*553.2 + xtg(it,40)*684.2 ); % MJ/NM3 end % Calculate dry gas heating value: hhvdry(it) = hhvgas(it)/(1-xtg(it,17)); % Calculate heat transfer at condenser (only condensing water) Hcondenserw(it)=H(17)+y(17)*18.015/1000*2442.5; %(kJ/kg-fuel); Water is condensed and cooled to 25C % Calculate heat transfer at condenser (water and other gases) Hcondenserwg(it)=totght(it)+y(17)*18.015/1000*2442.5; %cooled to 25C % Calculate heat for vaporising water and superheating steam; Water is heated from 25C Hsuperheat(it)=Uwatadd*(18.015/1000*2442.5+Dath(17,3)*T/1000 + Dath(17,4)*T^2/1000000 + Dath(17,5)/T + Dath(17,6)); %(kJ/kg-fuel) end % Normally end temperature iteration % (8) Preparing output report if M == 3 Cconv = 100.0*(1 - yt(:,21)/UC); % Carbon conversion vgdry = (summit - yt(:,17) - yt(:,9) - yt(:,N)) * 8.31448 * 298.15 / 100000; % vgdry = Dry gas yield (Nm3/kg fuel) vgwet = (summit - yt(:,N)) * 8.31448 * 298.15 / 100000; % vgwet = Wet gas yield (Nm3/kg fuel) E1 = 100 * (vgdry(:).* hhvdry(:) * 1000 + (dqt(:) <= 0) .* dqt(:))/(HHV * rfuel); % E1 = Gasif. Eff. E1 (%) excluding condensables E2 = 100 * (vgwet(:).* hhvgas(:) * 1000 + (dqt(:) <= 0) .* dqt(:))/(HHV * rfuel); % E2 = Gasif. Eff. E1 (%) including condensables elseif M == 4 Cconv = 100.0 * (1 - yt(:,33)/UC); vgdry = (summit - yt(:,17) - yt(:,9) - yt(:,N)) * 8.31448 * 298.15 / (1.01325*100000); vgwet = (summit - yt(:,N)) * 8.31448 * 298.15 / (1.01325*100000); Appendix J Matlab code for thermodynamic equilibrium calculation 197 A p p en d ices E1 = 100 * (vgdry(:).*hhvdry(:)*1000 + (dqt(:) <= 0) .* dqt(:))/(HHV*rfuel); E2 = 100 * (vgwet(:).*hhvgas(:)*1000 + (dqt(:) <= 0) .* dqt(:))/(HHV*rfuel); elseif M == 5 Cconv = 100.0 * (1 - yt(:,43)/UC); vgdry = (summit - yt(:,17) - yt(:,9) - yt(:,43)) * 8.31448 * 298.15 / (1.01325*100000); vgwet = (summit - yt(:,43)) * 8.31448 * 298.15 / (1.01325*100000); E1 = 100 * (vgdry(:).*hhvdry(:)*1000 + (dqt(:) <= 0) .* dqt(:))/(HHV*rfuel); E2 = 100 * (vgwet(:).*hhvgas(:)*1000 + (dqt(:) <= 0) .* dqt(:))/(HHV*rfuel); wt = zeros(NT,N); vgeach = zeros(NT,N); for i=1:N wt(:,i) = Dat2(i,10)*yt(:,i)/1000; vgeach(:,i) = yt(:,i) * 8.31448 * 298.15 / 100000; end end % (8.1) Major species statistics if M == 3 format long e report = 100*[TT(:)/100, xtdry(:,11), xtdry(:,14), xtdry(:,5), xtdry(:,15), xtdry(:,6) + xtdry(:,7) + xtdry(:,8) + xtdry(:,9), xtdry(:,21), xtg(:,17)]; disp('T, C(s), CH4, ,CO, CO2, H2, H2O') report = 100*[TT(:)/100, xt(:,21), xt(:,5), xt(:,14), xt(:,15), xt(:,11), xt(:,17)]; report elseif M == 4 ytc = [yt(:,5),yt(:,7),yt(:,14:15),yt(:,11),yt(:,17),yt(:,23),yt(:,22),yt(:,26),yt(:,33)]; % CH4, C2H4, CO, CO2, H2, H2O, HCN, N2, NH3, C(s) if NREP == 1 report(:,1) = TT(:); report(:,(1+iz)) = 100 * xt(:,33); elseif NREP == 2 report = 100 * [TT(:)/100, xtdry(:,14:15), xtdry(:,11), xtdry(:,5), yt(:,17)*2/(100*UH)]; end elseif M == 5 if NREP == 1 report = 100*[TT(:)/100, xt(:,43)]; elseif NREP == 2 report1 = 100 * [TT(:)/100, xtdry(:,14:15), xtdry(:,11), xtdry(:,5)]; elseif NREP == 3 % (8.2) Fate of elements - Elemental split spc(:,1) = yt(:,43)*1/EA0(1); % C(s) spc(:,2) = spc(:,1) + yt(:,5) /EA0(1); % CH4 spc(:,3) = spc(:,2) + yt(:,14)*1/EA0(1); % CO spc(:,4) = spc(:,3) + yt(:,15)*1/EA0(1); % CO2 spc(:,5) = spc(:,4) + yt(:,30)*1/EA0(1); % HCN sph(:,1) = yt(:,5) *4/EA0(2); % CH4 sph(:,1) = sph(:,1) + yt(:,7) *4/EA0(2); % C2H4 sph(:,2) = sph(:,1) + yt(:,11)*2/EA0(2); % H2 sph(:,3) = sph(:,2) + yt(:,17)*2/EA0(2); % H2O sph(:,4) = sph(:,3) + yt(:,10)*1/EA0(2); % H sph(:,4) = sph(:,4) + yt(:,31)*1/EA0(2); % HCN sph(:,4) = sph(:,4) + yt(:,26)*3/EA0(2); % NH3 Appendix J Matlab code for thermodynamic equilibrium calculation 198 A p p en d ices spo(:,1) = + yt(:,14)*1/EA0(3); % CO spo(:,2) = spo(:,1) + yt(:,15)*2/EA0(3); % CO2 spo(:,3) = spo(:,2) + yt(:,17)*1/EA0(3); % H2O spo(:,4) = spo(:,3) + yt(:,13)*2/EA0(3); % O2 spn(:,1) = (yt(:,30) + yt(:,31))*1/EA0(4); % HCN spn(:,2) = spn(:,1) + yt(:,22)*2/EA0(4); % N2 spn(:,3) = spn(:,2) + yt(:,26)*1/EA0(4); % NH3 sps(:,1) = (yt(:,36) + yt(:,37))*1/EA0(5); % SO2 + SO3 sps(:,2) = sps(:,1) + yt(:,38)*1/EA0(5); % COS sps(:,3) = sps(:,2) + yt(:,41)*1/EA0(5); % HS spo(:,4) = spo(:,3) + yt(:,42)*1/EA0(5); % H2S % Molar fraction of hydrogen that stays in H2O in the product. gama(:) = 100*yt(:,17)*2/UH; % ----------------------------------------- report0a = [TT(:)-273, TT(:), E1(:), hhvdry(:).*vgdry(:)*1000, Hcondenserw(:), Hcondenserwg(:), totsht(:), Hsuperheat(:), dqt(:), dqt(:)-Hsuperheat(:)]; report0b = [TT(:)-273, TT(:), E1(:), hhvdry(:).*vgdry(:)*1000*feedrate/1000/60, Hcondenserw(:)*feedrate/1000/60, Hcondenserwg(:)*feedrate/1000/60, totsht(:)*feedrate/1000/60, Hsuperheat(:)*feedrate/1000/60, dqt(:)*feedrate/1000/60, (dqt(:)- Hsuperheat(:))*feedrate/1000/60]; % Major speceis %T, H2, CO, CO2, CH4, C2+, N2, H2S, H2O, C(s), COS, SO, SO2, SO3, N2O, NO, NO2, NH3, HCN, SOX, NOX report1 = [TT(:)-273, TT(:), xtdry(:,11), xtdry(:,14), xtdry(:,15), xtdry(:,5), xtdry(:,6) + xtdry(:,7) + xtdry(:,8) + xtdry(:,9), xtdry(:,22), xtdry(:,42), xtdry(:,17), xtdry(:,43), xtdry(:,38), xtdry(:,35), xtdry(:,36), xtdry(:,37), xtdry(:,27), xtdry(:,28), xtdry(:,29), xtdry(:,26), xtdry(:,31), xtdry(:,35)+xtdry(:,36)+xtdry(:,37), xtdry(:,27)+xtdry(:,28)+xtdry(:,29)]; report2 = [TT(:)-273, TT(:), xtg(:,11), xtg(:,14), xtg(:,15), xtg(:,5), xtg(:,6) + xtg(:,7) + xtg(:,8) + xtg(:,9), xtg(:,22), xtg(:,42), xtg(:,17), xtg(:,43), xtg(:,38), xtg(:,35), xtg(:,36), xtg(:,37), xtg(:,27), xtg(:,28), xtg(:,29), xtg(:,26), xtg(:,31), xtg(:,35)+xtg(:,36)+xtg(:,37), xtg(:,27)+xtg(:,28)+xtg(:,29)]; report3 = [TT(:)-273, TT(:), xt(:,11), xt(:,14), xt(:,15), xt(:,5), xt(:,6) + xt(:,7) + xt(:,8) + xt(:,9), xt(:,22), xt(:,42), xt(:,17), xt(:,43), xt(:,38), xt(:,35), xt(:,36), xt(:,37), xt(:,27), xt(:,28), xt(:,29), xt(:,26), xt(:,31), xt(:,35)+xt(:,36)+xt(:,37), xt(:,27)+xt(:,28)+xt(:,29)]; report4 = [TT(:)-273, TT(:), xtdryNN(:,11), xtdryNN(:,14), xtdryNN(:,15), xtdryNN(:,5), xtdryNN(:,6) + xtdryNN(:,7) + xtdryNN(:,8) + xtdryNN(:,9), xtdryNN(:,22), xtdryNN(:,42), xtdryNN(:,17), xtdryNN(:,43), xtdryNN(:,38), xtdryNN(:,35), xtdryNN(:,36), xtdryNN(:,37), xtdryNN(:,27), xtdryNN(:,28), xtdryNN(:,29), xtdryNN(:,26), xtdryNN(:,31), xtdryNN(:,35)+xtdryNN(:,36)+xtdryNN(:,37), xtdryNN(:,27)+xtdryNN(:,28)+xtdryNN(:,29)]; report5 = [TT(:)-273, TT(:), yt(:,11), yt(:,14), yt(:,15), yt(:,5), yt(:,6) + yt(:,7) + yt(:,8) + yt(:,9), yt(:,22), yt(:,42), yt(:,17), yt(:,43), yt(:,38), yt(:,35), yt(:,36), yt(:,37), yt(:,27), yt(:,28), yt(:,29), yt(:,26), yt(:,31), yt(:,35)+yt(:,36)+yt(:,37), yt(:,27)+yt(:,28)+yt(:,29)]; report6 = [TT(:)-273, TT(:), wt(:,11), wt(:,14), wt(:,15), wt(:,5), wt(:,6) + wt(:,7) + wt(:,8) + wt(:,9), wt(:,22), wt(:,42), wt(:,17), wt(:,43), wt(:,38), wt(:,35), wt(:,36), wt(:,37), wt(:,27), wt(:,28), wt(:,29), wt(:,26), wt(:,31), wt(:,35)+wt(:,36)+wt(:,37), wt(:,27)+wt(:,28)+wt(:,29)]; report7 = [TT(:)-273, TT(:), vgeach(:,11), vgeach(:,14), vgeach(:,15), vgeach(:,5), vgeach(:,6) + vgeach(:,7) + vgeach(:,8) + vgeach(:,9), vgeach(:,22), vgeach(:,42), vgeach(:,17), vgeach(:,43), vgeach(:,38), vgeach(:,35), vgeach(:,36), vgeach(:,37), vgeach(:,27), vgeach(:,28), vgeach(:,29), vgeach(:,26), vgeach(:,31), vgeach(:,35)+vgeach(:,36)+vgeach(:,37), vgeach(:,27)+vgeach(:,28)+vgeach(:,29)]; report8 = [TT(:)-273, TT(:), xtdry(:,:)]; report9 = [TT(:)-273, TT(:), xtg(:,:)]; report10 = [TT(:)-273, TT(:), xt(:,:)]; report11 = [TT(:)-273, TT(:), xtdryNN(:,:)]; report12 = [TT(:)-273, TT(:), yt(:,:)]; Appendix J Matlab code for thermodynamic equilibrium calculation 199 A p p en d ices report13 = [TT(:)-273, TT(:), wt(:,:)]; report14 = [TT(:)-273, TT(:), vgeach(:,:)]; % Conversion and efficiency report15 = [xtdry(:,26), xtdry(:,40), Cconv(:), gama(:), hhvdry(:), vgdry(:), 100000*hhvdry(:).*vgdry(:)/HHV, dqt(:) ]; % Minor species report16 = 1000000*[ xtdry(:,5:9), xtdry(:,26:31), xtdry(:,36:38), xtdry(:,42) ]; % (ppm) CH4-C3H8 NH3-HCN SO2,SO3,COS H2S % The smallest species is not reported, but calculated by difference. report17 = [TT(:), spc(:,1:4), sph(:,1:3), spo(:,1:3), spn(:,1:2), sps(:,1:3)]; % C split H split O split N split N split S split current_alfa = alfa; current_alfa; % EA0' % Uwat report1 report2 report3 report4 %File output format datenow=datestr(datevec(now),21); fileid1='F'; fileid2=num2str(NF,'%03.0f'); %Fuel type fileid3='P'; fileid4=num2str(p*10,'%03.0f'); %Pressure [Bar*10] fileid5='S'; fileid6=num2str(rH2O,'%03.0f'); %S/C [mol%] fileid7='C'; fileid8=num2str(Charcont*100,'%03.0f'); %Char ratio [wt% (100*kg/kg-biooil-wet)] fileid9='O'; fileid10=num2str(alpha*100,'%03.0f'); %Oxygen ratio [stoi. ratio mol%] fileid11='NP'; fileid12=num2str(N2purge*10,'%03.0f'); %N2 purge rate [Nm3/min] fileid13='FR'; fileid14=num2str(feedrate*10,'%03.0f'); %Fuel feeding rate [g/min] expansion='.txt'; fileid=strcat(fileid1,fileid2,fileid3,fileid4,fileid5,fileid6,fileid7,fileid8,fileid9,fileid10,fi leid11,fileid12,fileid13,fileid14); filename=strcat(fileid,expansion); fid = fopen(uiputfile(filename),'w'); fprintf(fid,'%s\n',datenow); fprintf(fid,'Condition_ID: %s\n',fileid); fprintf(fid,'Fuel_type: %1.0f\n',NF); fprintf(fid,'Fuel_feed_rate: %15.9f kg/hr\n',rfuel); fprintf(fid,'Pressure: %7.3f bar\n', p); fprintf(fid,'H2O/C: %7.3f mol/mol\n', rH2O); fprintf(fid,'Water-add/fuel: %7.3f kg/kg\n', 18.015/12.011*Dat3(5,NF)/100*(1- Dat3(14,NF)/100)-Dat3(14,NF)/100); fprintf(fid,'Water_addition(steam): %7.3f kg/kg-fuel\n', Uwatadd*18.015/1000); fprintf(fid,'Actual_water_addition: %7.3f g/min\n', Uwatadd*18.015*feedrate/1000); fprintf(fid,'Char_ratio: %7.3f kg/kg\n', Charcont); fprintf(fid,'Oxygen_ratio: %7.3f mol/mol stoic.-ratio\n', alpha); Appendix J Matlab code for thermodynamic equilibrium calculation 200 A p p en d ices fprintf(fid,'N2_purge_rate: %8.3f L/min\n', N2purge); fprintf(fid,'Fuel_HHV: %15.9f kJ/kg-wet-fuel\n', HHV); fprintf(fid,'Fuel_feeding_rate: %8.3f g/min\n', feedrate); fprintf(fid,'Fuel_temperature_preheated: %7.1f C\n', tfuel); fprintf(fid,'Enthoropy_for-preheating-fuel: %15.9f kJ/kg-fuel\n', hfuel); fprintf(fid,'Enthoropy_for-preheating-fuel: %15.9f kJ/kg-fuel\n', hfuel*feedrate/1000/60); fprintf(fid,'N2-purge_temperature: %7.1f C\n', tnitro); fprintf(fid,'Enthoropy_N2-purge: %15.9f kJ/kg-fuel\n', hN2purge); fprintf(fid,'Number_of_elements_considered= %s\n', num2str(M)); fprintf(fid,'Number_of_species_considered= %s\n', num2str(N)); fprintf(fid,'Number_of_gaseous_species= %s\n', num2str(ngas)); fprintf(fid,'Number_of_liquid_species= %s\n', num2str(nliq)); fprintf(fid,'Number_of_solid_species= %s\n', num2str(nsol)); fprintf(fid,'Number_of_components= %s\n', num2str(NC)); fprintf(fid,'Number_of_phases_involved= %s\n', num2str(NP)); fprintf(fid,'Stoichiometric_moles_of_O2= %s (mole/kg_fuel)\n', num2str(Tm0*10)); fprintf(fid,'Stoichiometric_air_of_fuel= %s (Nm3/kg_fuel)\n', num2str(V0)); fprintf(fid,'Total_air_supply= %s (Nm3/hr)\n', num2str(Vair)); fprintf(fid,'Higher_heating_value_of_fuel= %s (kJ/kg_wet-fuel)\n', num2str(HHV)); fprintf(fid,'Enthalpy_of_feed= %s (kJ/kg_fuel)\n', num2str(Hfeed)); fprintf(fid,'Rank_of_RAND_coefficient_matrix= %s\n', num2str(ra1)); fprintf(fid,'Condition_number_of_RAND_matrix= %s\n', num2str(ra2)); fprintf(fid,'\n'); %fprintf(fid,'Heat_input-loss kJ/kg-fuel\n'); %fprintf(fid,' T[C] T[K] Cold-gas-eff. HHV-drygas H_condenser_H2O H_condenser_tot H_lost_ash H_steam Total_H_input H_absorbed_in_reactor\n'); %fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report0a .'); %fprintf(fid,'\n'); %fprintf(fid,'Actual_Heat_input-loss kW\n'); %fprintf(fid,' T[C] T[K] Cold-gas-eff. HHV-drygas H_condenser_H2O H_condenser_tot H_lost_ash H_steam Total_H_input H_absorbed_in_reactor\n'); %fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report0b .'); %fprintf(fid,'\n'); fprintf(fid,'Each_species_mol_fraction_in_dry-gas__(xtdry)\n'); fprintf(fid,' T[C] T[K] H2 CO CO2 CH4 C2+ N2 H2S H2O C(s) COS SO SO2 SO3 N2O NO NO2 NH3 HCN SOX NOX\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report1.'); fprintf(fid,'\n'); fprintf(fid,'Each_gas_species_mol_fraction_in_wet-gas__(xtg)\n'); fprintf(fid,'Total_water_in_fuel %15.9f\n', Uwat); fprintf(fid,'Water_added_to_bio-oil %15.9f\n', Uwatadd); fprintf(fid,' T[C] T[K] H2 CO CO2 CH4 C2+ N2 H2S H2O C(s) COS SO SO2 SO3 N2O NO NO2 NH3 HCN SOX NOX\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report2.'); fprintf(fid,'\n'); fprintf(fid,'Each_species_mol_fraction__(xt)\n'); fprintf(fid,' T[C] T[K] H2 CO CO2 CH4 C2+ N2 H2S H2O C(s) COS SO SO2 SO3 N2O NO NO2 NH3 HCN SOX NOX\n'); Appendix J Matlab code for thermodynamic equilibrium calculation 201 A p p en d ices fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report3.'); fprintf(fid,'\n'); fprintf(fid,'Each_species_mol_fraction_in_dry-N2free-gas__(xtdryNN)\n'); fprintf(fid,' T[C] T[K] H2 CO CO2 CH4 C2+ N2 H2S H2O C(s) COS SO SO2 SO3 N2O NO NO2 NH3 HCN SOX NOX\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report4.'); fprintf(fid,'\n'); fprintf(fid,'Each_gas_species_amount_in_mol/hr__(yt)\n'); fprintf(fid,'Total_water_in_fuel %15.9f\n', Uwat ); fprintf(fid,'Water_added_to_bio-oil %15.9f\n', Uwatadd ); fprintf(fid,' T[C] T[K] H2 CO CO2 CH4 C2+ N2 H2S H2O C(s) COS SO SO2 SO3 N2O NO NO2 NH3 HCN SOX NOX\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report5.'); fprintf(fid,'\n'); fprintf(fid,'Each_gas_species_amount_in_kg/hr__(wt)\n'); fprintf(fid,'Total_water_in_fuel %15.9f\n', Uwat*18.0153/1000 ); fprintf(fid,'Water_added_to_bio-oil %15.9f\n', Uwatadd*18.0153/1000 ); fprintf(fid,' T[C] T[K] H2 CO CO2 CH4 C2+ N2 H2S H2O C(s) COS SO SO2 SO3 N2O NO NO2 NH3 HCN SOX NOX\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report6.'); fprintf(fid,'\n'); fprintf(fid,'Each_gas_species_volume_in_Nm3/hr__(vgeach)\n'); fprintf(fid,'Total_water_in_fuel %15.9f\n', Uwat * 8.31448 * 298.15 / 100000); fprintf(fid,'Water_added_to_bio-oil %15.9f\n', Uwatadd* 8.31448 * 298.15 / 100000); fprintf(fid,' T[C] T[K] H2 CO CO2 CH4 C2+ N2 H2S H2O C(s) COS SO SO2 SO3 N2O NO NO2 NH3 HCN SOX NOX\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report7.'); fprintf(fid,'\n'); fprintf(fid,'xtdry\n'); fprintf(fid,' Species_number - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44\n'); fprintf(fid,' T[C] T[K] C-g CH CH2 CH3 CH4 C2H2 C2H4 C2H6 C3H8 H H2 O O2 CO CO2 OH H2O(g) H2O2 HCO HO2 N N2 NCO NH NH2 NH3 N2O NO NO2 CN HCN HCNO S-g S2-g SO SO2 SO3 COS CS CS2 HS H2S C-s S-s\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f % 15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report8.'); fprintf(fid,'\n'); fprintf(fid,'xtg\n'); fprintf(fid,' Species_number - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44\n'); fprintf(fid,' T[C] T[K] C-g CH CH2 CH3 CH4 C2H2 C2H4 C2H6 C3H8 H H2 O O2 CO CO2 OH H2O(g) H2O2 HCO HO2 N N2 NCO NH NH2 NH3 N2O NO NO2 CN HCN HCNO S-g S2-g SO SO2 SO3 COS CS CS2 HS H2S C-s S-s\n'); Appendix J Matlab code for thermodynamic equilibrium calculation 202 A p p en d ices fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f % 15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report9.'); fprintf(fid,'\n'); fprintf(fid,'xt\n'); fprintf(fid,' Species_number - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44\n'); fprintf(fid,' T[C] T[K] C-g CH CH2 CH3 CH4 C2H2 C2H4 C2H6 C3H8 H H2 O O2 CO CO2 OH H2O(g) H2O2 HCO HO2 N N2 NCO NH NH2 NH3 N2O NO NO2 CN HCN HCNO S-g S2-g SO SO2 SO3 COS CS CS2 HS H2S C-s S-s\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f % 15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report10.'); fprintf(fid,'\n'); fprintf(fid,'xtdryNN\n'); fprintf(fid,' Species_number - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44\n'); fprintf(fid,' T[C] T[K] C-g CH CH2 CH3 CH4 C2H2 C2H4 C2H6 C3H8 H H2 O O2 CO CO2 OH H2O(g) H2O2 HCO HO2 N N2 NCO NH NH2 NH3 N2O NO NO2 CN HCN HCNO S-g S2-g SO SO2 SO3 COS CS CS2 HS H2S C-s S-s\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f % 15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report11.'); fprintf(fid,'\n'); fprintf(fid,'yt\n'); fprintf(fid,' Species_number - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44\n'); fprintf(fid,' T[C] T[K] C-g CH CH2 CH3 CH4 C2H2 C2H4 C2H6 C3H8 H H2 O O2 CO CO2 OH H2O(g) H2O2 HCO HO2 N N2 NCO NH NH2 NH3 N2O NO NO2 CN HCN HCNO S-g S2-g SO SO2 SO3 COS CS CS2 HS H2S C-s S-s\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f % 15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report12.'); fprintf(fid,'\n'); fprintf(fid,'wt\n'); fprintf(fid,' Species_number - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44\n'); fprintf(fid,' T[C] T[K] C-g CH CH2 CH3 CH4 C2H2 C2H4 C2H6 C3H8 H H2 O O2 CO CO2 OH H2O(g) H2O2 HCO HO2 N N2 NCO NH NH2 NH3 N2O NO NO2 CN HCN HCNO S-g S2-g SO SO2 SO3 COS CS CS2 HS H2S C-s S-s\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f % 15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report13.'); fprintf(fid,'\n'); fprintf(fid,'vgeach\n'); fprintf(fid,' Species_number - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44\n'); fprintf(fid,' T[C] T[K] C-g CH CH2 CH3 CH4 C2H2 C2H4 C2H6 C3H8 H H2 O O2 CO CO2 OH H2O(g) H2O2 HCO HO2 N N2 NCO NH NH2 NH3 N2O NO NO2 CN HCN HCNO S-g S2-g SO SO2 SO3 COS CS CS2 HS H2S C-s S-s\n'); fprintf(fid,'%6.0f %6.0f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %1 5.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f % 15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f %15.9f\n',report14.'); fclose(fid); Appendix J Matlab code for thermodynamic equilibrium calculation 203 A p p en d ices end end % --------------------------------------------- end % End of outer-layer pressure/alpha/iz iteration % End of the FEM equilibrium model program. Appendix J Matlab code for thermodynamic equilibrium calculation 204 A p p en d ices J.2 Thermodynamic database File name: coaldat.m Function: Thermodynamic, chemical and fuel property database for the equilibrium model. The database is designed for a maximum of 8 elements, 77 species --------------------------------------------------------------------------------- function [Dat1, Dat11, Dat2, Dat3, Dath, Dath1] = coaldat(NE) % COALDAT chooses species and generates data for FEM algorithm based on the number of elements. disp(' ') disp(' DATA FOR COAL AND BIOMASS COMBUSTION / GASIFICATION MODEL ') disp(' ') disp(' Version 1.0 Masakazu Sakaguchi modified Xiantial Li’s code (Jan. 3, 2010) ') disp(' ') % (1) Thermodynamic data % Dat1 - Thermodynamic data. Source: JANAF (1985). Unit: kJ/mol, P = 1 bar % col 1 = species index % col 2 = phase index (1 = gas, 2 = liquid, 3 = solid) % col 3~7= 5 correlation factors of DGfo(T) % col 8 = cut-off temperature above which alternative correlations are used % col 9 = species identification % Form of correlations % dGfo(T,i) = Dat1(i,3) + Dat1(i,4)*T*log(T) + Dat1(i,5)*T^2 + Dat1(i,6)/T + Dat1(i,7)*T; data1 =[ % Gaseous species - the first ideal solution % NP a b c d e T Species 1 1 718.7355 -0.0031881 1.9694E-06 -349.8554 -0.137650 3000 % C-g 2 1 598.0953 0.0043862 -1.9285E-07 -343.7758 -0.146320 3000 % CH 3 1 389.5788 0.0077494 -6.6767E-07 -144.1515 -0.110660 3000 % CH2 4 1 149.0231 0.014182 -2.9054E-06 41.6868 -0.084363 3000 % CH3 5 1 -71.8931 0.02432 -6.5597E-06 362.4270 -0.070448 3000 % CH4 6 1 237.5202 0.033256 1.0033E-06 -100.2833 -0.152990 3000 % C2H2 7 1 54.1895 0.021684 -5.6205E-06 449.8686 -0.079724 3000 % C2H4 8 1 -81.0970 0.043877 -1.7094E-05 1355.4000 -0.095520 3000 % C2H6 9 1 350.4716 0.66056 -2.6670E-04 -46636.1389 -4.40930 1600 % C3H8 10 1 215.7586 -0.0073886 9.1095E-07 10.6162 -0.000162 3000 % H 11 1 0 0 0 0 0 3000 % H2 12 1 248.3877 -0.0052751 8.6902E-07 -86.4689 -0.025042 3000 % O 13 1 0 0 0 0 0 3000 % O2 14 1 -106.8226 0.0033849 1.2143E-06 -326.6449 -0.117690 3000 % CO 15 1 -392.9600 0.0012695 3.3456E-07 -11.6092 -0.012005 3000 % CO2 16 1 40.3471 0.0020491 -1.2972E-07 -99.8727 -0.030869 3000 % OH 17 1 -239.0906 0.010852 -2.2307E-06 18.3029 -0.026247 3000 % H2O 18 1 -123.5618 0.033093 -1.6006E-05 -333.1775 -0.117240 3000 % H2O2 19 1 45.1098 0.0055998 1.4897E-07 34.6607 -0.088745 3000 % HCO 20 1 2.4359 0.0054918 -1.5372E-06 135.5294 0.007803 3000 % HO2 Appendix J Matlab code for thermodynamic equilibrium calculation 205 A p p en d ices 21 1 471.1519 -0.0062291 8.7182E-07 -24.5552 -0.016799 3000 % N 22 1 0 0 0 0 0 3000 % N2 23 1 158.6539 -0.0028993 1.1294E-06 6.8426 -0.009485 3000 % NCO 24 1 376.9439 0.00071778 -2.6308E-07 -27.3018 -0.025106 3000 % NH 25 1 190.2236 0.0071296 -1.8680E-06 302.7894 -0.011408 3000 % NH2 26 1 -44.8484 0.01514 -4.8125E-06 333.6023 0.006629 3000 % NH3 27 1 78.2427 -0.0042333 -3.3034E-07 327.3182 0.107480 3000 % N2O 28 1 90.1960 -0.0004493 1.5852E-07 -9.4708 -0.009467 3000 % NO 29 1 30.8041 -0.00073718 -9.3478E-08 255.6206 0.069885 3000 % NO2 30 1 435.7871 -0.0052945 3.2164E-05 97.4931 -0.050972 1300 % CN 31 1 136.4484 0.0032993 -3.0523E-07 -42.9127 -0.057570 3000 % HCN 32 1 -101.6731 0.0035636 -4.1540E-07 135.7470 0.009485 3000 % HCNO 33 1 289.7121 0.034221 -1.2994E-05 -591.9209 -0.363310 882 % S-g 34 1 160.9443 0.094171 -4.0715E-05 -1257.4685 -0.783600 882 % S2 35 1 8.5516 0.0041034 2.1502E-05 -115.6319 -0.127750 882 % SO 36 1 -292.1318 0.010504 1.6770E-05 -64.8202 -0.090967 882 % SO2 37 1 -391.3302 0.013933 1.1711E-05 62.5729 -0.015461 882 % SO3 38 1 -137.0166 -0.0030409 2.6447E-05 -46.3667 -0.085981 882 % COS 39 1 348.7762 0.13911 -3.3397E-05 -3564.5543 -1.145700 3000 % CS 40 1 121.0552 -0.0025409 4.9600E-05 -177.7956 -0.180370 882 % CS2 41 1 170.4059 0.061514 -1.7989E-05 -1712.5844 -0.544870 3000 % HS 42 1 -11.1102 0.023046 1.3079E-05 -244.5911 -0.207000 822 % H2S 43 1 120.0283 -0.0050448 7.4745E-07 -18.0719 -0.020620 3000 % Cl 44 1 0 0 0 0 0 3000 % Cl2 45 1 -91.0771 0.0039131 -7.9513E-07 -34.6297 -0.035919 3000 % HCl 46 1 117.6082 0.033919 -1.5573E-05 -331.9480 -0.321700 1171 % Na 47 1 -187.8035 0.035312 -1.8113E-05 -242.8665 -0.235570 1171 % NaOH 48 1 -1072.0630 -0.11214 1.4202E-04 2227.5049 0.900530 1171 % Na2SO4 49 1 -169.6071 0.038915 -1.8283E-05 -363.5927 -0.318660 1171 % NaCl-g 50 1 180.2741 0.00016753 1.2421E-05 -123.7122 -0.124680 1773 % Ca-g 51 1 40.7320 -0.011558 1.9722E-05 224.1673 -0.007229 1773 % CaO-g 52 1 -618.3319 -0.018033 1.9297E-05 574.4943 0.207910 1773 %Ca(OH)2 53 1 185.7102 0.11895 -8.1082E-06 -3158.4494 -1.006700 1773 % CaS-g % Liquid species - the second ideal solution 54 2 0 0 0 0 0 1171 % Na-l 55 2 -445.9895 -0.11189 3.6991E-05 6703.4883 0.910340 1171 % Na2O-l 56 2 -459.3828 -0.074551 2.3967E-05 3491.8695 0.664410 1171 % NaOH-l 57 2 -1512.0850 -0.65586 3.1344E-04 36973.2297 4.841900 1171 % Na2CO3 58 2 -770.5716 -0.83388 5.2169E-04 37800.9203 5.676300 1171 % Na2S-l 59 2 -1805.6090 -0.83986 5.0615E-04 37729.5329 6.081200 1171 % Na2SO4 60 2 -397.4964 0.0027913 -1.6935E-05 1717.7270 0.076591 1171 % NaCl-l 61 2 -195.1217 -0.03771 5.8557E-06 -2560.3111 0.382540 2500 % Ca-l 62 2 -566.7801 -0.027185 1.9285E-05 418.3720 0.257940 1773 % CaO-l % Solids - single-species phases 63 3 0 0 0 0 0 3000 % C-s 64 3 0 0 0 0 0 3000 % S-s 65 3 -436.2111 -0.038132 2.9169E-05 1030.1304 0.389390 1171 % Na2O-s 66 3 -435.1112 -0.0062054 -2.2299E-05 595.9177 0.221760 1171 % NaOH-s 67 3 -1156.8340 -0.053051 2.3470E-05 1404.1967 0.645620 1171 % Na2CO3 68 3 -811.0560 -0.8308 5.1991E-04 37657.5045 5.686700 1171 % Na2S-s 69 3 -1799.7500 -0.78703 4.7835E-04 35304.4574 5.737200 1171 % Na2SO4 70 3 -402.2163 0.02726 -2.2745E-05 -443.3801 -0.081660 1171 % NaCl-s 71 3 0 0 0 0 0 1773 % Ca-s 72 3 -644.5782 -0.026871 1.9067E-05 466.1628 0.280090 1773 % CaO-s 73 3 -996.2730 -0.022354 4.4400E-06 596.7389 0.447650 1000 %Ca(OH)2 74 3 -1241.8400 -0.071011 3.4234E-05 2447.3300 0.745000 1200 % CaCO3 75 3 -417.4180 0.10164 -7.0773E-06 -2991.0648 -0.713070 1773 % CaS-s Appendix J Matlab code for thermodynamic equilibrium calculation 206 A p p en d ices 76 3 -1412.6200 0.050125 -1.1297E-06 -312.6500 0.024180 2000 % CaSO4 77 3 -818.1100 -0.0857846 2.8497E-05 -178.0300 0.741505 1112 % CaCl2 ]; data11 = [ % Gaseous species - the first ideal solution % NP a b c d e T Species 1 1 718.7355 -0.0031881 1.9694E-06 -349.8554 -0.137650 3000 % C-g 2 1 598.0953 0.0043862 -1.9285E-07 -343.7758 -0.146320 3000 % CH 3 1 389.5788 0.0077494 -6.6767E-07 -144.1515 -0.110660 3000 % CH2 4 1 149.0231 0.0141820 -2.9054E-06 41.6868 -0.084363 3000 % CH3 5 1 -71.8931 0.0243200 -6.5597E-06 362.4270 -0.070448 3000 % CH4 6 1 237.5202 0.0332560 1.0033E-06 -100.2833 -0.152990 3000 % C2H2 7 1 54.1895 0.0216840 -5.6205E-06 449.8686 -0.079724 3000 % C2H4 8 1 -81.0970 0.0438770 -1.7094E-05 1355.4000 -0.095520 3000 % C2H6 9 1 350.4716 0.6605600 -2.6670E-04 -46636.1389 -4.40930 1600 % C3H8 10 1 215.7586 -0.0073886 9.1095E-07 10.6162 -0.000162 3000 % H 11 1 0 0 0 0 0 3000 % H2 12 1 248.3877 -0.0052751 8.6902E-07 -86.4689 -0.025042 3000 % O 13 1 0 0 0 0 0 3000 % O2 14 1 -106.8226 0.0033849 1.2143E-06 -326.6449 -0.117690 3000 % CO 15 1 -392.9600 0.0012695 3.3456E-07 -11.6092 -0.012005 3000 % CO2 16 1 40.3471 0.0020491 -1.2972E-07 -99.8727 -0.030869 3000 % OH 17 1 -239.0906 0.0108520 -2.2307E-06 18.3029 -0.026247 3000 % H2O 18 1 -123.5618 0.0330930 -1.6006E-05 -333.1775 -0.117240 3000 % H2O2 19 1 45.1098 0.0055998 1.4897E-07 34.6607 -0.088745 3000 % HCO 20 1 2.4359 0.0054918 -1.5372E-06 135.5294 0.007803 3000 % HO2 21 1 471.1519 -0.0062291 8.7182E-07 -24.5552 -0.016799 3000 % N 22 1 0 0 0 0 0 3000 % N2 23 1 158.6539 -0.0028993 1.1294E-06 6.8426 -0.009485 3000 % NCO 24 1 376.9439 0.00071778 -2.6308E-07 -27.3018 -0.025106 3000 % NH 25 1 190.2236 0.0071296 -1.8680E-06 302.7894 -0.011408 3000 % NH2 26 1 -44.8484 0.0151400 -4.8125E-06 333.6023 0.006629 3000 % NH3 27 1 78.2427 -0.0042333 -3.3034E-07 327.3182 0.107480 3000 % N2O 28 1 90.1960 -0.0004493 1.5852E-07 -9.4708 -0.009467 3000 % NO 29 1 30.8041 -0.00073718 -9.3478E-08 255.6206 0.069885 3000 % NO2 30 1 164.8626 0.0531160 -1.7015E-05 115377.2750 -0.267280 3000 % CN 31 1 136.4484 0.0032993 -3.0523E-07 -42.9127 -0.057570 3000 % HCN 32 1 -101.6731 0.0035636 -4.1540E-07 135.7470 0.009485 3000 % HCNO 33 1 216.5859 -0.0012033 9.4057E-08 -920.1499 -0.051352 3000 % S-g 34 1 0 0 0 0 0 3000 % S2-g 35 1 -58.3392 0.00071189 -1.0075E-07 -230.9811 -0.010629 3000 % SO 36 1 -366.2515 -0.0040415 8.4388E-07 546.8531 0.104060 3000 % SO2 37 1 -472.4207 -0.0114260 1.5682E-06 1474.2158 0.254670 3000 % SO3 38 1 -203.0049 -0.0012573 8.5715E-07 128.0412 -0.001837 3000 % COS 39 1 348.7762 0.1391100 -3.3397E-05 -3564.5543 -1.145700 3000 % CS 40 1 -9.9250 -0.0017091 1.0910E-06 -455.0825 0.003789 3000 % CS2 41 1 170.4059 0.0615140 -1.7989E-05 -1712.5844 -0.544870 3000 % HS 42 1 -95.1612 -0.0016036 1.2867E-07 1797.0360 0.063333 3000 % H2S 43 1 120.0283 -0.0050448 7.4745E-07 -18.0719 -0.020620 3000 % Cl 44 1 0 0 0 0 0 3000 % Cl2 45 1 -91.0771 0.0039131 -7.9513E-07 -34.6297 -0.035919 3000 % HCl 46 1 0 0 0 0 0 3000 % Na-g 47 1 -307.5971 -0.0028573 2.4583E-07 162.7579 0.114810 3000 % NaOH-g 48 1 -1979.1620 -0.2721400 3.0537E-05 264780.0380 2.748800 3000 % Na2SO4 49 1 -288.8874 0.0012026 2.3460E-08 56.2872 0.028103 3000 % NaCl-g 50 1 0 0 0 0 0 3000 % Ca-g 51 1 -120.2318 0.0171030 -6.8175E-06 -566.2313 -0.082174 3000 % CaO-g 52 1 -779.1250 -0.0138330 1.6886E-06 -263.4823 0.309010 3000 %Ca(OH)2 Appendix J Matlab code for thermodynamic equilibrium calculation 207 A p p en d ices 53 1 -135.1063 -0.0052293 -2.6241E-06 -380.4109 0.091046 3000 % CaS-g % Liquid species - the second ideal solution 54 2 -102.0722 0.00027844 -3.8827E-06 31.9057 0.089756 1600 % Na-l 55 2 -603.1522 -0.0483350 9.7810E-07 641.5320 0.642100 3000 % Na2O-l 56 2 -532.4731 -0.0368850 3.8832E-06 -307.9617 0.486990 2500 % NaOH-l 57 2 -1357.4400 -0.0777160 2.8704E-06 -126.2168 1.012900 2500 % Na2CO3 58 2 -615.2298 -0.0331660 7.0543E-07 -50.4397 0.521040 3000 % Na2S-l 59 2 -1664.5100 -0.0717650 2.9858E-06 -181.8829 1.147800 3000 % Na2SO4 60 2 -505.1877 -0.0281640 3.1939E-07 -70.9886 0.368450 2500 % NaCl-l 61 2 -195.1217 -0.0377100 5.8557E-06 -2560.3111 0.382540 2500 % Ca-l 62 2 -725.6541 -0.0173170 -5.6041E-07 -991.9894 0.318130 3000 % CaO-l % Solids - single-species phases 63 3 0 0 0 0 0 3000 % C-s 64 3 0 0 0 0 0 3000 % S-s 65 3 -713.7362 -0.1176400 2.1687E-05 4547.5904 1.192000 2000 % Na2O-s 66 3 2469.6893 4.8916000 -1.8881E-03 125735.7140 -34.769600 1500 % NaOH-s 67 3 -1387.7580 -0.0645030 -9.0077E-06 -198.6146 0.960480 2000 % Na2CO3 68 3 -769.4582 -0.1608900 2.5916E-05 1662.5306 1.519800 2000 % Na2S-s 69 3 -1590.6950 0.0073529 -4.5470E-05 0 0.632690 1500 % Na2SO4 70 3 -2490.9921 4.9294000 -1.9042E-03 126100.0000 -35.077000 1500 % NaCl-s 71 3 0 0 0 0 0 1773 % Ca-s 72 3 -799.9182 -0.0168030 -3.0821E-07 -309.0810 0.337110 3000 % CaO-s 73 3 -996.2730 -0.0223540 4.4400E-06 596.7389 0.447650 1000 %Ca(OH)2 74 3 -1241.8400 -0.0710110 3.4234E-05 2447.3300 0.745000 1200 % CaCO3 75 3 -700.9383 -0.0146900 -4.0703E-07 -158.3563 0.313420 3000 % CaS-s 76 3 -1412.6200 0.0501250 -1.1297E-06 -312.6500 0.024180 2000 % CaSO4 77 3 -818.1100 -0.0857846 2.8497E-05 -178.0300 0.741505 1112 % CaCl2 ]; % Dath - Heat of formation and correlation factors for enthalpy. % Data from Pankratz (1982, 1984, 1987) Unit: kJ/mol. % Ref. pressure: 1 atm (1.013 bar) for 38 species given in Pankratz's books, % 1 bar for all other species (JANAF data). % Water occurs as H2O (g), otherwise wrong. % col 1 = species index % col 2 = phase index % col 3~6 = correlation factors for enthalpy % col 7 = heat of formation of the species (kJ/mol) % col 8 = temperature range of application % col 9 = species identification % Ho(T)-Ho(298) = aT/1000 + bT^2/1000000 + cT^-1 + d datah = [ % Gaseous species % NP a b c d DHfo(298) T Species 1 1 20.7192 0.037656 -8.7864 -6.15048 716.670 2000 % C-g 2 1 27.6313 2.7448 41.0016 -8.8832 594.128 3000 % CH 3 1 38.6452 3.7555 408.7690 -14.0607 386.392 3000 % CH2 4 1 47.3888 6.2452 784.6346 -18.7179 145.687 3000 % CH3 5 1 52.9240 9.9567 1405.2934 -24.1768 -74.873 3000 % CH4 6 1 57.6040 5.8194 1046.3957 -22.4273 226.731 3000 % C2H2 7 1 73.3320 10.869 2132.0253 -33.4348 52.467 3000 % C2H4 Appendix J Matlab code for thermodynamic equilibrium calculation 208 A p p en d ices 8 1 70.7250 27.312 4372.6784 -37.9474 -84.000 3000 % C2H6 9 1 103.2600 43.4030 878.3933 -19.1280 -103.847 3000 % C3H8 10 1 20.7861 0 0 -6.19650 217.999 3000 % H 11 1 27.0119 1.753096 -69.0360 -7.97889 0 3000 % H2 12 1 20.8656 -0.012552 -93.7216 -5.90362 249.173 3000 % O 13 1 30.2503 2.104552 189.1168 -9.84077 0 2000 % O2 14 1 28.0663 2.3138 25.9408 -8.6609 -110.527 2000 % CO 15 1 45.3671 4.342992 961.9016 -17.13766 -393.522 2000 % CO2 16 1 26.5977 1.991584 -195.8112 -7.45170 38.987 3000 % OH 17 1 28.8487 6.029144 -100.4160 -8.79895 -241.826 2000 % H2O(g) 18 1 42.7186 9.547888 541.4096 -15.4013 -136.106 1500 % H2O2 19 1 42.0411 3.1052 554.7696 -15.7137 43.514 3000 % HCO 20 1 37.1539 5.054272 467.7712 -13.09592 2.092 3000 % HO2 21 1 20.7861 0 0 -6.19650 472.683 3000 % N 22 1 27.2671 2.464376 -33.0536 -8.23830 0 2000 % N2 23 1 51.8911 2.0775 770.5358 -19.2298 159.410 3000 % NCO 24 1 27.8197 1.8458 12.6111 -8.6206 376.560 3000 % NH 25 1 34.0257 4.4683 214.1698 -11.8113 190.372 3000 % NH2 26 1 43.1447 7.1278 724.6100 -17.3521 -45.898 3000 % NH3 27 1 44.2918 5.045904 771.5296 -16.24229 82.048 3000 % N2O 28 1 28.1541 2.615 -11.2968 -8.58975 90.291 2000 % NO 29 1 41.4174 4.966408 658.1432 -14.99546 33.095 2000 % NO2 30 1 28.8052 2.2265 58.6635 -9.1533 435.136 1300 % CN 31 1 43.7801 3.4977 615.5683 -16.264 135.143 3000 % HCN 32 1 59.8200 4.1845 1030.9512 -22.9877 -101.671 3000 % HCNO 33 1 22.5810 -0.472792 -122.1728 -6.28018 276.980 2000 % S-g 34 1 34.9071 1.33888 285.7672 -11.48508 128.600 2000 % S2-g 35 1 32.8737 1.577368 323.4232 -11.02484 5.007 2000 % SO 36 1 47.3796 3.330464 843.9128 -17.25482 -296.842 2000 % SO2 37 1 67.0109 4.389016 1685.7336 -26.02448 -395.765 882 % SO3 38 1 49.4884 3.652632 899.5600 -18.0958 -138.407 2000 % COS 39 1 33.4302 0.995792 375.7232 -11.31772 280.328 3000 % CS 40 1 56.3815 1.5756 714.1594 -20.0176 116.943 3000 % CS2 41 1 28.6646 1.916272 -234.7224 -7.92868 139.327 2500 % HS 42 1 31.5515 6.71532 121.3360 -10.40979 -20.502 2000 % H2S 43 1 23.9450 -0.719648 149.3688 -7.57722 121.302 2000 % Cl 44 1 36.9322 0.368192 285.7672 -12.0039 0 3000 % Cl2 45 1 26.7190 2.359776 -89.9560 -7.87429 -92.312 2000 % HCl 46 1 20.7652 0.016736 -1.2552 -6.18814 107.300 3000 % Na-g 47 1 51.9505 1.6391 346.7762 -16.9438 -197.757 3000 % NaOH-g 48 1 14.4120 2.915 2366.9623 -53.1502 -1033.620 3000 % Na2SO4 49 1 37.2358 0.3858 118.9968 -11.5661 -181.418 3000 % NaCl-g 50 1 19.8067 0.3758 -571.4430 -5.6241 177.800 3000 % Ca-g 51 1 23.0042 6.5738 -410.8451 -5.0186 43.932 3000 % CaO-g 52 1 85.9217 3.571 991.8630 -29.7821 -610.764 3000 %Ca(OH)2 53 1 24.3673 7.2837 -331.7881 -6.0861 123.595 3000 % CaS-g % Liquid species - the second ideal solution 54 2 29.3047 -0.38493 -380.3256 -5.03754 0 1171 % Na-l 55 2 104.6000 0 0 -31.186 -372.843 3000 % Na2O-l 56 2 88.5501 -2.5713 -180.4221 -25.6167 -416.878 2500 % NaOH-l 57 2 209.0100 -4.1645 12222.2540 -102.5933 -1108.520 2500 % Na2CO3 58 2 932.3960 -284.8718 0 -626.9640 -323.940 1445 % Na2S-l 59 2 21.1740 -3.3885 8801.9448 90.8069 -1356.390 3000 % Na2SO4 60 2 42.0032 11.19638 -161.9208 -12.97458 -385.923 1171 % NaCl-l 61 2 18.2956 11.2672 -24.5763 -6.4483 0 1171 % Ca-l 62 2 48.9970 2.514 573.2851 -16.8339 -557.335 2100 % CaO-l % Solids - single-species phases Appendix J Matlab code for thermodynamic equilibrium calculation 209 A p p en d ices 63 3 14.7193 3.204944 720.9032 -7.09188 0 2000 % C-s 64 3 31.8890 -2.1803 -1884.7120 -3.0467 0 882 % S-s 65 3 55.9694 20.572728 -78.2408 -18.25479 -417.982 1300 % Na2O-s 66 3 108.4800 -8.7382 1892.2624 -38.4824 -425.931 1500 % NaOH-s 67 3 126.2500 28.23 1673.3871 -46.939 -1130.770 2000 % Na2CO3 68 3 74.8308 9.9286 -182.4224 -22.5810 -336.100 1100 % Na2S-s 69 3 87.4047 58.426 -4393.8200 -16.7088 -1379.290 1500 % Na2SO4 70 3 42.0032 11.196384 -161.9208 -12.97458 -411.120 1074 % NaCl-s 71 3 30.8253 6.845 560.9676 -12.8472 0 1773 % Ca-s 72 3 48.9970 2.514 573.2851 -16.8339 -635.089 2100 % CaO-s 73 3 91.6459 14.7372 941.6648 -31.6522 -986.085 1000 %Ca(OH)2 74 3 97.9350 14.198 1855.4379 -36.8346 -1207.600 1200 % CaCO3 75 3 49.9402 2.117104 334.3016 -16.20045 -473.210 2000 % CaS-s 76 3 32.8630 61.278 -6316.0380 4.5425 -1434.110 2000 % CaSO4 77 3 69.8393 7.694376 159.4104 -22.04131 -795.400 1045 % CaCl2 ]; datah1 = [ % Gaseous species % NP a b c d DHfo(298) T Species 1 1 18.4891 0.48116 -2158.9440 -2.38906 716.670 3000 % C-g 2 1 27.6313 2.7448 41.0016 -8.8832 594.128 3000 % CH 3 1 38.6452 3.7555 408.7690 -14.0607 386.392 3000 % CH2 4 1 47.3888 6.2452 784.6346 -18.7179 145.687 3000 % CH3 5 1 52.9240 9.9567 1405.2934 -24.1768 -74.873 3000 % CH4 6 1 57.6040 5.8194 1046.3957 -22.4273 226.731 3000 % C2H2 7 1 73.3320 10.869 2132.0253 -33.4348 52.467 3000 % C2H4 8 1 70.7250 27.312 4372.6784 -37.9474 -84.000 3000 % C2H6 9 1 103.2600 43.4030 878.3933 -19.1280 -103.847 3000 % C3H8 10 1 20.7861 0 0 -6.19650 217.999 3000 % H 11 1 27.0119 1.753096 -69.0360 -7.97889 0 3000 % H2 12 1 20.8656 -0.012552 -93.7216 -5.90362 249.173 3000 % O 13 1 34.8946 0.874456 2635.9200 -15.43059 0 3000 % O2 14 1 34.2084 0.5188 0 -13.7528 -110.527 3000 % CO 15 1 61.3835 0.309616 9056.6864 -37.08279 -393.522 3000 % CO2 16 1 26.5977 1.991584 -195.8112 -7.45170 38.987 3000 % OH 17 1 28.8487 6.029144 -100.4160 -8.79895 -241.826 2000 % H2O(g) 18 1 42.7186 9.547888 541.4096 -15.4013 -136.106 1500 % H2O2 19 1 42.0411 3.1052 554.7696 -15.7137 43.514 3000 % HCO 20 1 37.1539 5.054272 467.7712 -13.09592 2.092 3000 % HO2 21 1 20.7861 0 0 -6.19650 472.683 3000 % N 22 1 36.1707 0.234304 4568.9280 -19.42631 0 3000 % N2 23 1 51.8911 2.0775 770.5358 -19.2298 159.410 3000 % NCO 24 1 27.8197 1.8458 12.6111 -8.6206 376.560 3000 % NH 25 1 34.0257 4.4683 214.1698 -11.8113 190.372 3000 % NH2 26 1 43.1447 7.1278 724.6100 -17.3521 -45.898 3000 % NH3 27 1 44.2918 5.045904 771.5296 -16.24229 82.048 3000 % N2O 28 1 28.1541 2.615 -11.2968 -8.58975 90.291 2000 % NO 29 1 41.4174 4.966408 658.1432 -14.99546 33.095 2000 % NO2 30 1 28.8052 2.2265 58.6635 -9.1533 435.136 1300 % CN 31 1 43.7801 3.4977 615.5683 -16.264 135.143 3000 % HCN 32 1 59.8200 4.1845 1030.9512 -22.9877 -101.671 3000 % HCNO 33 1 17.3887 0.702912 -4331.2770 1.50624 276.980 3000 % S-g 34 1 39.7898 0.4184 5271.8400 -20.06228 128.600 3000 % S2-g 35 1 37.3087 0.665256 4993.6040 -18.58114 5.007 3000 % SO 36 1 58.3333 0.288696 5014.9424 -29.0788 -296.842 3000 % SO2 37 1 79.1404 0.573208 1163.9888 -34.76067 -395.765 3000 % SO3 38 1 49.4884 3.652632 899.5600 -18.0958 -138.407 2000 % COS Appendix J Matlab code for thermodynamic equilibrium calculation 210 A p p en d ices 39 1 33.4302 0.995792 375.7232 -11.31772 280.328 3000 % CS 40 1 56.3815 1.5756 714.1594 -20.0176 116.943 3000 % CS2 41 1 28.6646 1.916272 -234.7224 -7.92868 139.327 2500 % HS 42 1 31.5515 6.71532 121.3360 -10.40979 -20.502 2000 % H2S 43 1 23.0915 -0.326352 1771.9240 -8.25503 121.302 3000 % Cl 44 1 36.9322 0.368192 285.7672 -12.0039 0 3000 % Cl2 45 1 34.2460 0.598312 4134.6288 -17.99538 -92.312 3000 % HCl 46 1 20.7652 0.016736 -1.2552 -6.18814 107.300 3000 % Na-g 47 1 51.9505 1.6391 346.7762 -16.9438 -197.757 3000 % NaOH-g 48 1 14.4120 2.915 2366.9623 -53.1502 -1033.620 3000 % Na2SO4 49 1 37.2358 0.3858 118.9968 -11.5661 -181.418 3000 % NaCl-g 50 1 19.8067 0.3758 -571.4430 -5.6241 177.800 3000 % Ca-g 51 1 23.0042 6.5738 -410.8451 -5.0186 43.932 3000 % CaO-g 52 1 85.9217 3.571 991.8630 -29.7821 -610.764 3000 %Ca(OH)2 53 1 24.3673 7.2837 -331.7881 -6.0861 123.595 3000 % CaS-g % Liquid species - the second ideal solution 54 2 29.3047 -0.38493 -380.3256 -5.03754 0 1171 % Na-l 55 2 104.6000 0 0 -31.186 -372.843 3000 % Na2O-l 56 2 88.5501 -2.5713 -180.4221 -25.6167 -416.878 2500 % NaOH-l 57 2 209.0100 -4.1645 12222.2540 -102.5933 -1108.520 2500 % Na2CO3 58 2 92.0480 0 0 11.7989 -323.940 2000 % Na2S-l 59 2 21.1740 -3.3885 8801.9448 90.8069 -1356.390 3000 % Na2SO4 60 2 68.4502 0 0 -0.33054 -385.923 1800 % NaCl-l 61 2 35.0000 0 0 -2.648 0 2500 % Ca-l 62 2 62.7600 0 0 -28.193 -557.335 3000 % CaO-l % Solids - single-species phases 63 3 23.6019 0.560656 3012.4800 -15.42641 0 3000 % C-s 64 3 31.8890 -2.1803 -1884.7120 -3.0467 0 882 % S-s 65 3 55.9694 20.572728 -78.2408 -18.25479 -417.982 1300 % Na2O-s 66 3 108.4800 -8.7382 1892.2624 -38.4824 -425.931 1500 % NaOH-s 67 3 126.2500 28.23 1673.3871 -46.939 -1130.770 2000 % Na2CO3 68 3 -582.2747 310.5239 0 336.3476 -336.100 1276 % Na2S-s 69 3 87.4047 58.426 -4393.8200 -16.7088 -1379.290 1500 % Na2SO4 70 3 68.4502 0 0 -0.33054 -411.120 1800 % NaCl-s 71 3 5.2567 3.407 -27056.4100 212.0632 0 3000 % Ca-s 72 3 51.2990 1.9775 1301.8968 -13.8306 -635.089 3000 % CaO-s 73 3 91.6459 14.7372 941.6648 -31.6522 -986.085 1000 %Ca(OH)2 74 3 97.9350 14.198 1855.4379 -36.8346 -1207.600 1200 % CaCO3 75 3 49.9402 2.117104 334.3016 -16.20045 -473.210 2000 % CaS-s 76 3 32.8630 61.278 -6316.0380 4.5425 -1434.110 2000 % CaSO4 77 3 122.2690 -7.451704 -70.2912 -31.91137 -795.400 1600 % CaCl2 ]; % (2) Species-element matrix (SEM) % ---------------------------------------------------------- % Data2 - Basic chemical data % col 1 = species index % col 2~9 = species-element matrix % col 10 = molecular weight of a species data2 = [ % Group 1 - gases % C H O N S Cl Na Ca M. wt Species Appendix J Matlab code for thermodynamic equilibrium calculation 211 A p p en d ices 1 1 0 0 0 0 0 0 0 12.011 % C-g 2 1 1 0 0 0 0 0 0 13.0189 % CH 3 1 2 0 0 0 0 0 0 14.0269 % CH2 4 1 3 0 0 0 0 0 0 15.0348 % CH3 5 1 4 0 0 0 0 0 0 16.0428 % CH4 6 2 2 0 0 0 0 0 0 26.0379 % C2H2 7 2 4 0 0 0 0 0 0 28.0538 % C2H4 8 2 6 0 0 0 0 0 0 30.0696 % C2H6 9 3 8 0 0 0 0 0 0 44.6565 % C3H8 10 0 1 0 0 0 0 0 0 1.00794 % H 11 0 2 0 0 0 0 0 0 2.01588 % H2 12 0 0 1 0 0 0 0 0 15.9994 % O 13 0 0 2 0 0 0 0 0 31.9988 % O2 14 1 0 1 0 0 0 0 0 28.0104 % CO 15 1 0 2 0 0 0 0 0 44.0098 % CO2 16 0 1 1 0 0 0 0 0 17.0073 % OH 17 0 2 1 0 0 0 0 0 18.0153 % H2O 18 0 2 2 0 0 0 0 0 34.0147 % H2O2 19 1 1 1 0 0 0 0 0 29.0183 % HCO 20 0 1 2 0 0 0 0 0 33.0067 % HO2 21 0 0 0 1 0 0 0 0 14.0067 % N 22 0 0 0 2 0 0 0 0 28.0135 % N2 23 1 0 1 1 0 0 0 0 42.0171 % NCO 24 0 1 0 1 0 0 0 0 15.0147 % NH 25 0 2 0 1 0 0 0 0 16.0226 % NH2 26 0 3 0 1 0 0 0 0 17.0306 % NH3 27 0 0 1 2 0 0 0 0 44.0129 % N2O 28 0 0 1 1 0 0 0 0 30.0061 % NO 29 0 0 2 1 0 0 0 0 46.0055 % NO2 30 1 0 0 1 0 0 0 0 26.0177 % CN 31 1 1 0 1 0 0 0 0 27.0257 % HCN 32 1 1 1 1 0 0 0 0 43.0251 % HCNO 33 0 0 0 0 1 0 0 0 32.066 % S-g 34 0 0 0 0 2 0 0 0 64.132 % S2-g 35 0 0 1 0 1 0 0 0 48.0654 % SO 36 0 0 2 0 1 0 0 0 64.0648 % SO2 37 0 0 3 0 1 0 0 0 80.0642 % SO3 38 1 0 1 0 1 0 0 0 60.0764 % COS 39 1 0 0 0 1 0 0 0 44.077 % CS 40 1 0 0 0 2 0 0 0 76.143 % CS2 41 0 1 0 0 1 0 0 0 33.0739 % HS 42 0 2 0 0 1 0 0 0 34.0819 % H2S 43 0 0 0 0 0 1 0 0 35.4527 % Cl 44 0 0 0 0 0 2 0 0 70.9054 % Cl2 45 0 1 0 0 0 1 0 0 36.4606 % HCl 46 0 0 0 0 0 0 1 0 22.9898 % Na-g 47 0 1 1 0 0 0 1 0 39.9971 % NaOH-g 48 0 0 4 0 1 0 2 0 142.043 % Na2SO4-g 49 0 0 0 0 0 1 1 0 58.4425 % NaCl-g 50 0 0 0 0 0 0 0 1 40.078 % Ca-g 51 0 0 1 0 0 0 0 1 56.0774 % CaO-g 52 0 2 2 0 0 0 0 1 74.0927 % Ca(OH)2-g 53 0 0 0 0 1 0 0 1 72.144 % CaS-g % Group 2 - liquids 54 0 0 0 0 0 0 1 0 22.9898 % Na-l 55 0 0 1 0 0 0 2 0 61.9789 % Na2O-l 56 0 1 1 0 0 0 1 0 39.9971 % NaOH-l 57 1 0 3 0 0 0 2 0 105.989 % Na2CO3-l 58 0 0 0 0 1 0 2 0 78.0455 % Na2S-l Appendix J Matlab code for thermodynamic equilibrium calculation 212 A p p en d ices 59 0 0 4 0 1 0 2 0 142.043 % NaSO4-l 60 0 0 0 0 0 1 1 0 58.4425 % NaCl-l 61 0 0 0 0 0 0 0 1 40.078 % Ca-l 62 0 0 1 0 0 0 0 1 56.0774 % CaO-l % Group 3 - solids 63 1 0 0 0 0 0 0 0 12.011 % C-s 64 0 0 0 0 1 0 0 0 32.066 % S-s 65 0 0 1 0 0 0 2 0 61.9789 % Na2O-s 66 0 1 1 0 0 0 1 0 39.9971 % NaOH-s 67 1 0 3 0 0 0 2 0 105.989 % Na2CO3 68 0 0 0 0 1 0 2 0 78.0455 % Na2S-s 69 0 0 4 0 1 0 2 0 142.043 % NaSO4-s 70 0 0 0 0 0 1 1 0 58.4425 % NaCl-s 71 0 0 0 0 0 0 0 1 40.078 % Ca-s 72 0 0 1 0 0 0 0 1 56.0774 % CaO-s 73 0 2 2 0 0 0 0 1 74.0927 % Ca(OH)2-s 74 1 0 3 0 0 0 0 1 100.087 % CaCO3-s 75 0 0 0 0 1 0 0 1 72.144 % CaS-s 76 0 0 4 0 1 0 0 1 136.142 % CaSO4-s 77 0 0 0 0 0 2 0 1 110.983 % CaCl2-s ]; % (3) Fuel analyses % ----------------------------------------- % Data3 - Fuel data data3 = [ % Sawdust species % Proximate analysis (as received basis, wt %) - 10 species maximum. % 1 2 3 4 5 6 7 8 9 % Highv Cypr SPF Heml SPF Ced/H PBS Mix-1 Mix-2 0 27.1 0 0 0 0 0 0 0 % Volatile matter 0 67.1 0 0 0 0 0 0 0 % Fixed carbon 0 5.8 0 0 0 0 0 0 0 % Ash 0 2.3 0 0 0 0 0 0 0 % Moisture % Ultimate analysis (dry base, wt ==(Bio-oil is also on the dry basis)==) % Bio-oil on the wet basis: C 42.47; H 6.89; O 50.04; N 0.3; S 0.3 % 1 2 3 4 5 6 7 8 9 %Biooil(WL) Char(WL) ModC ModC2 - - - - - 56.7933 78.442 99.96 99.96 0.0 0.0 0.0 0.0 0.0 % C 5.88115 3.5284 0.01 0.01 0.0 0.0 0.0 0.0 0.0 % H 36.523 17.396 0.01 0.01 0.0 0.0 0.0 0.0 0.0 % O 0.40118 0.32644 0.01 0.01 0.0 0.0 0.0 0.0 0.0 % N 0.40118 0.32644 0.01 0.01 0.0 0.0 0.0 0.0 0.0 % S 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 % Cl 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 % Na 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 % Ca 0.0 5.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 % Ash 25.22 2.3 0.0 50.0 0.0 0.0 0.0 0.0 0.0 % Moisture 25.65 0.0 20.55 20.55 0.0 0.0 0.0 0.0 0.0 % HHV (MJ/kg) ]; Appendix J Matlab code for thermodynamic equilibrium calculation 213 A p p en d ices % Select species to be considered in the sub-set with NE elements Dat1 = [ ]; % Initialization Dat11 = [ ]; Dat2 = [ ]; Dat3 = [ ]; Dath = [ ]; Dath1 = [ ]; if NE == 1 % C Dat1 = [ data1(1,:); data1(63,:)]; Dat11 = [data11(1,:); data11(63,:)]; Dat2 = [ data2(1,:); data2(63,:)]; Dath = [ datah(1,:); datah(63,:)]; Dath1 = [datah1(1,:); datah1(63,:)]; elseif NE == 2 % C-H Dat1 = [ data1(1:11,:); data1(63,:)]; Dat11 = [data11(1:11,:); data11(63,:)]; Dat2 = [ data2(1:11,:); data2(63,:)]; Dath = [ datah(1:11,:); datah(63,:)]; Dath1 = [datah1(1:11,:); datah1(63,:)]; elseif NE == 3 % C-H-O Dat1 = [ data1(1:20,:); data1(63,:)]; Dat11 = [data11(1:20,:); data11(63,:)]; Dat2 = [ data2(1:20,:); data2(63,:)]; Dath = [ datah(1:20,:); datah(63,:)]; Dath1 = [datah1(1:20,:); datah1(63,:)]; elseif NE == 4 % C-H-O-N Dat1 = [ data1(1:32,:); data1(63,:)]; Dat11 = [data11(1:32,:); data11(63,:)]; Dat2 = [ data2(1:32,:); data2(63,:)]; Dath = [ datah(1:32,:); datah(63,:)]; Dath1 = [datah1(1:32,:); datah1(63,:)]; elseif NE == 5 % C-H-O-N-S Dat1 = [ data1(1:42,:); data1(63:64,:)]; Dat11 = [data11(1:42,:); data11(63:64,:)]; Dat2 = [ data2(1:42,:); data2(63:64,:)]; Dath = [ datah(1:42,:); datah(63:64,:)]; Dath1 = [datah1(1:42,:); datah1(63:64,:)]; elseif NE == 6 % C-H-O-N-S-Cl Dat1 = [ data1(1:45,:); data1(63:64,:)]; Dat11 = [data11(1:45,:); data11(63:64,:)]; Dat2 = [ data2(1:45,:); data2(63:64,:)]; Dath = [ datah(1:45,:); datah(63:64,:)]; Dath1 = [datah1(1:45,:); datah1(63:64,:)]; elseif NE == 7 % C-H-O-N-S-Cl-Na Dat1 = [ data1(1:49,:); data1(54:60,:); data1(63:70,:)]; Dat11 = [data11(1:49,:); data11(54:60,:); data11(63:70,:)]; Dat2 = [ data2(1:49,:); data2(54:60,:); data2(63:70,:)]; Dath = [ datah(1:49,:); datah(54:60,:); datah(63:70,:)]; Dath1 = [datah1(1:49,:); datah1(54:60,:); datah1(63:70,:)]; elseif NE == 8 Dat1 = data1; Dat11 = data11; Dat2 = data2; Dath = datah; Dath1 = datah1; end Dat3 = data3; Appendix J Matlab code for thermodynamic equilibrium calculation 214 A p p en d ices disp(' Chemical, thermodynamic and fuel analysis data') disp(' for coal and biomass combustion/gasification is successfully loaded.') disp(' ') Appendix J Matlab code for thermodynamic equilibrium calculation 215 A p p en d ices J.3 Elemental abundance File name: abundsd.m Function: To calculate the abundance of each element present in the system --------------------------------------------------------------------------------- function [EA0,CEA,V0,Vair,mair,Uwat,Uwatadd,Hfeed,hfuel,hN2purge,HHV,hff,Conv,Tm0,tfuel,tnitro] = abundsd(NE,Dat3,rfuel,rH2O,NF,NO,NANA,NFIT,alfa,Ca,Charcont,tstm,N2purge,feedrate,TotalCyield,YCh ydroc,YHhydroc) % ABUNDSD calculates element abundance from sawdust, oxidant, and steam data % Last update: Jan 2, 2010 Version 1.0 Masakazu Sakaguchi modified Xiantial Li’s code (Jan. 3, 2010) % Hydrocarbon modified version 1.0 % The total abundance of an element is the sum of its abundances in main fuel, auxiliary fuel, air, steam, and sorbent % All calculations are based on 1kg of feedstock (dry basis). % Make sure that all ultimate analyses of feedstocks are on dry basis Moistoil=Dat3(14,NF)/100; Moistchar=Dat3(14,NF+1)/100; Car = (1-Charcont)*Dat3(5,NF)*(1-Moistoil)+ Charcont*(1-Moistchar)*Dat3(5,NF+1); Har = (1-Charcont)*(Dat3(6,NF)*(1-Moistoil)) + Charcont*((1-Moistchar)*Dat3(6,NF+1)); Oar = (1-Charcont)*(Dat3(7,NF)*(1-Moistoil)) + Charcont*((1-Moistchar)*Dat3(7,NF+1)); Nar = (1-Charcont)*Dat3(8,NF)*(1-Moistoil)+ Charcont*(1-Moistchar)*Dat3(8,NF+1); Sar = (1-Charcont)*Dat3(9,NF)*(1-Moistoil)+ Charcont*(1-Moistchar)*Dat3(9,NF+1); Clar = (1-Charcont)*Dat3(10,NF)*(1-Moistoil)+ Charcont*(1-Moistchar)*Dat3(10,NF+1); Naar = (1-Charcont)*Dat3(11,NF)*(1-Moistoil)+ Charcont*(1-Moistchar)*Dat3(11,NF+1); Caar = (1-Charcont)*Dat3(12,NF)*(1-Moistoil)+ Charcont*(1-Moistchar)*Dat3(12,NF+1); UCasor = 0; % (1) Calculate moles of each element Conv1 = 100; Conv2 = 0; % Initialization UCint = Car*rfuel*1000/(12.011*100); if NFIT == 0 Conv = 100; elseif NFIT == 1 % An experimental carbon conversion, (%) Conv1 = TotalCyield; Conv2 = YChydroc; Conv = Conv1 - Conv2; end UC = UCint*Conv/100; % Moles of C entering equilibrium UHint = Har*rfuel*1000/(1.00794*100); UH0 = 2*UCint*rH2O; % Each mol H2O contains 2 mol H UHext = UH0; if NFIT == 1 % The actual moles of H that enters the equilibrium system Conv3 = YHhydroc; DUHhydro = UHint*Conv3/100; % Moles of carbon deducted as CH4 UH = UH0 + UHint - DUHhydro; Appendix J Matlab code for thermodynamic equilibrium calculation 216 A p p en d ices else UH = UH0 + UHint; end Uwat = UCint*rH2O; %totmoist*1000/18.0153; Uwatadd = Uwat - ((1-Charcont)*Moistoil+Charcont*Moistchar)*rfuel*1000/(18.0153); % Uwat denotes external moisture added to the dry base, mol/kg_dryfuel if Uwat <= 0.000001 Uwat = 0.000001; end UOint = Oar*rfuel*1000/(15.9994*100); % UOint does not include O from the ash-bound oxygen if NE < 5 Tm0 = Car/12.011+ (Har/1.00794)/4.0 - (Oar/15.9994)/2.0; else Tm0 = Car/12.011+ (Har/1.00794)/4.0 - (Oar/15.9994)/2.0 + Sar/32.066; end % Tm0 is the total moles of O2 (not O) required to burn 100g of fuel if NO == 1 % Stoichiometric air @ 298K, 1.013 bar (Nm3/kg_dry sawdust): V0 = (Tm0)/100*1000*8.314472*298.15/101325.027*100/20.9476; else % Stoichiometric pure oxygen (Nm3/kg_dry fuel): V0 = (Tm0)/100*1000*8.314472*298.15/101325.027*100/99.992; end Vair = V0*rfuel*alfa; % Nm3/hr @ 1atm, 298 K % mair = (Tm0/0.209476) * 28.964 * 10 * rfuel * alfa; % (gram/hr) % mair includes the weight of minor species (Ar, Ne, etc.) in air. % So mair can be calculated with another formula: mair = (Tm0*31.9988 + Tm0*(0.78084/0.209476)*28.0135 + Tm0*(0.000314/0.209476)*44.0098)*rfuel*10*alfa; % (gram/hr) if NO == 1 UOair = 2 * Tm0 * alfa *(10* rfuel) * (1 + 0.000314/0.209476); % One mole of O2 contains 2 moles of O atoms % One mole of air also contains 0.000314 mole of CO2 else UOair = 2 * Tm0 * (rfuel*1000/100)*alfa; % One mole of O2 contains 2 moles of O atoms end UOext = UHext/2.0; % Oxygen that comes from total moisture UOsor = 0.0; UOmoist = rfuel*1000/(15.9994*100)*((1-Charcont)*(Moistoil*100*15.9994/18.0153) + Charcont*(Moistchar*100 *15.9994/18.0153)); UO = UOint + UOair + UOext + UOsor;% + UOmoist; % UOint must be added because it has been subtracted from UOair. % If the oxidant is air, modify the C abundance due to CO2 in air. if NO == 1 UC = UC + 0.000314*Tm0*(rfuel*1000/100)*alfa; end UNint = Nar*rfuel*1000/(14.0067*100); % mol/hr UNext = 2*(N2purge*60/1000)*101300/(8.314472*298.15)*(rfuel*1000/(feedrate*60)); % mol/hr if NO == 1 UNair = (78.084/20.9476)*UOair; % The N/O molar ratio in air else UNair = UOair*0.008/99.992; % Ind. grade oxygen has 0.008% N2 Appendix J Matlab code for thermodynamic equilibrium calculation 217 A p p en d ices end UN = UNint + UNair + UNext; if NE >=5 US = Sar * rfuel * 1000 / (32.066*100); UCasor = Ca * US; % Sorvent for sulfur retention end if NE >= 6 UCl = Clar * rfuel * 1000 / (35.4527*100); end if NE >= 7 UNa = Naar * rfuel * 1000 / (22.9898*100); end if NE >= 8 UCaint = Caar * rfuel * 1000 / (40.078*100); UCatot = Ca*(US + UCl); % Moles of Ca needed to remove S and Cl UCasor = UCatot - UCaint; % Total externally added Ca (sorbent) purity = 96.5 / 100; % Purity of sorbent rsorb = UCasor * 56.0774 / (purity*1000); % Sorbent feed rate (kg/hr) Caconv = 1.0/Ca; % Ca conversion UCa = UCatot * Caconv; % The actual mol of Ca entering equilibrium end % --------------------------------------------- EA0 = zeros(NE,1); % Initialization of EA0 if NE == 2 EA0 = [UC; UH]; elseif NE == 3 EA0 = [UC; UH; UO]; elseif NE == 4 EA0 = [UC; UH; UO; UN]; elseif NE == 5 EA0 = [UC; UH; UO; UN; US]; elseif NE == 6 EA0 = [UC; UH; UO; UN; US; UCl]; elseif NE == 7 EA0 = [UC; UH; UO; UN; US; UCl; UNa]; elseif NE == 8 EA0 = [UC; UH; UO; UN; US; UCl; UNa; UCa]; end % ----------------------------------------- if NF >= 10 EA0 = zeros(NE,1); end CEA = EA0; % (2) Calculate enthalpy of feedstock tfuel = 60; % fuel temperature(deg C) tmoist = tfuel; tsorb = 25; toxy = 150; tsurr = 25; Appendix J Matlab code for thermodynamic equilibrium calculation 218 A p p en d ices hstm = 25; tnitro = 25; %N2purge temperature hsorb = 0; % (3) The heat of formation of fuel % Assume the molecular weight of the fuel is 100. % The chemical formula of the fuel is C_a1 H_a2 O_a3 N_a4 S_a5 af = zeros(8,1); ar2db = 100/(100-Dat3(14,NF)); % ar2db > 1 ar2daf = 100/(100-Dat3(13,NF)-Dat3(14,NF)); % ar2daf > 1. Conversion factor from ar base to daf base af(1) = Dat3(5,NF)/12.011; % C af(2) = Dat3(6,NF)/1.00794; % H af(3) = Dat3(7,NF)/15.9994; % O af(4) = Dat3(8,NF)/14.0067; % N af(5) = Dat3(9,NF)/32.066; % S af(6) = Dat3(10,NF)/35.453; % Cl af(7) = Dat3(11,NF)/22.9898; % Na af(8) = Dat3(12,NF)/40.078; % Ca % HHVdaf in kJ/kg, dry ash free base %hhvdaf = HHV * ar2daf; % Don't remove this line! Daf base (kJ/kg) HHVdb = 341*Dat3(5,NF) + 1322*Dat3(6,NF) - 120*(Dat3(7,NF)+Dat3(8,NF)) - 15.3*Dat3(13,NF) + 68.6*Dat3(9,NF); % kJ/kg_dry Thermodynamic data for biomass materials and waste components/sponsored by the ASME research committee on industrial and municipal wastes; edited by E.S.Domalski, T.L.Jobe,Jr., T.A.Milne, pp339 HHV = HHVdb/ar2db; % Now calculate the heat of formation of the fuel (H2O in liq. state) % a1 C + a1 O2 = a1 CO2 a1 * (-393.522) kJ/mol % a2/2 H2 + a2/4 O2 = a2/2 H2O a2/2 * (-285.840) kJ/mol % a5 S + a5 O2 = a5 SO2 a5 * (-286.842) kJ/mol % a1 CO2 + a2/2 H2O = a4/2 N2 + ... = Fuel + Tm0 O2 + 79/21* Tm0 N2 % The heat of formation of the fuel is: hff = HHV - 10*(af(1)*393.509 + af(2)/2*285.83 + af(5)*296.83 + (Uwat/1000)*285.83); % kJ/kg_coal (ar basis), TRC Thermodynamic Tables - Hydrocarbons, Thermodynamics Research Center, Texas A&M Univ. System, College Station, Texas; "The NBS Tables of Chemical Themodynamic Properties," J. Physical and Chemical Reference Data, vol. 11, supp.2, 1982. hfuel = (tfuel-25)*3.2; %(kJ/kg-fuel(any types)) if NO == 1 % air cpoxy = 8.31448*(3.355 + 0.575*(toxy + 273.15)/1000 - 0.016 * (1/(toxy +273.15)^2)*100000)/1000; % kJ/mol.K else % Oxygen cpoxy = 8.31448*(3.639 + 0.506*(toxy + 273.15)/1000 - 0.227 * (1/(toxy +273.15)^2)*100000)/1000; % kJ/mol.K end cpsorb = 8.31448*(6.104 + 0.443*(tsorb + 273.15)/1000 - 1.047 * (1/(tsorb +273.15)^2)*100000)/1000; % kJ/mol.K cpstm = 8.31448*(3.470 + 1.450*(tstm + 273.15)/1000 + 0.121 * (1/(tstm +273.15)^2)*100000)/1000; % kJ/mol.K cpstmliq= 8.31448*(8.712 + 1.25*(tstm + 273.15)/1000 - 0.18 * ((tstm +273.15)^2)/1000000)/1000; % kJ/mol.K cpnitro= 8.31448*(3.280 + 0.593*(tnitro + 273.15)/1000 + 0.04 * (1/(tnitro +273.15)^2)*100000)/1000; % kJ/mol.K if NO == 1 moxy = (Tm0/0.209476)*alfa*rfuel; % moles of air Appendix J Matlab code for thermodynamic equilibrium calculation 219 A p p en d ices else moxy = (Tm0/0.99992) *alfa*rfuel; end hN2purge=cpnitro * UNext*(tnitro-25); % kJ hoxy = cpoxy * moxy *(toxy-25); % kJ hsorb = cpsorb* UCasor*(tsorb-25); % kJ if tstm >= 100 hstm = cpstm * UOext *(tstm-25); % kJ else hstm = cpstmliq * UOext *(tstm-25) - 2442.5 * UOext * 18.015/1000; %kJ end % This line implies that water and steam are added at the same T. Hfeed = hfuel + hN2purge + hoxy + hstm + hsorb; disp(' ') disp([' Stoichiometric moles of O2 = ' num2str(Tm0) ' (mole/100g dry fuel) ']) disp([' Stoichiometric air of fuel = ' num2str(V0) ' (Nm3/kg_dry fuel) ']) disp([' Total air supply = ' num2str(Vair) ' (Nm3/hr) ']) disp([' Higher heating value of fuel= ' num2str(HHV) ' (kJ/kg dry fuel) ']) disp([' Enthalpy of feed = ' num2str(Hfeed) ' (kJ/kg fuel) ' ]) disp(' ') Appendix J Matlab code for thermodynamic equilibrium calculation 220 A p p en d ices J.4 Molar fraction of each species File name: calcc.m Function: To calculate the current molar fraction of each species --------------------------------------------------------------------------------- function [cy,ys,x,xg,xs,EA,CEA] = calcc(SI,SEM,y,EA0) % CALCC updates the current molar fractions and element abundance vector with new y results. % Version 1.0 Masakazu Sakaguchi modified Xiantial Li’s code (Jan. 3, 2010) [N,M] = size(SEM); NP = 1; % One homogeneous phase ytot = 0; ytot1 = 0; ytot2 = 0; x = zeros(N,1); % Overall molar fraction of species i xg = zeros(N,1); % Molar fraction of species i in gas phase xl = zeros(N,1); % Molar fraction of species i in liquid phase cy = zeros(N,M); % Element distribution in each species EA = zeros(M,1); % Overall element abundance ns = zeros(N,1); % Count the number of single-species phases m = 0; nliq = 0; for i = 1:N if SI(i) ~= 1 if SI(i) == 2 nliq = nliq + 1; end m = m + 1; ns(i) = m; end end ys = zeros(m,1); xs = ones(m,1); NP = NP + m; CEA = zeros(M,NP); for k = 1:m for i=1:N if ns(i) == k ys(k) = y(i); end end end % Compute the species split of each element, cy for i = 1:N for j = 1:M cy(i,j) = y(i)*SEM(i,j)/EA0(j); end end for i = 1:N Appendix J Matlab code for thermodynamic equilibrium calculation 221 A p p en d ices ytot = ytot + y(i); ytot1 = ytot1 + (SI(i) == 1) * y(i); % Gas phase ytot2 = ytot2 + (SI(i) == 2) * y(i); % Liquid phase end x = y/ytot; % Overall rduced molar fraction for i = 1:N if SI(i) == 1 xg(i) = y(i)/ytot1; % Reduced molar fraction in gas phase elseif SI(i) == 2 xl(i) = y(i)/ytot2; % Reduced molar fraction in liquid phase end end % Calculate a new EA and CEA for iteration for j = 1:M for i = 1:N EA(j) = EA(j) + y(i)*SEM(i,j); if SI(i) == 1 dirac = 1.0; else dirac = 0.0; end CEA(j,1) = CEA(j,1) + y(i)*dirac*SEM(i,j); % Gas if nliq >= 1 CEA(j,2) = CEA(j,2) + y(i)*(SI(i) == 2)*SEM(i,j); % Liquid phase % M == 7 or 8 % CEA(j,3) = C(s) % CEA(j,4) = S(s), .... else if M == 3 CEA(j,2) = y(N)*SEM(N,j); % Solid phases 1 = C(s) elseif M == 4 CEA(j,2) = y(N)*SEM(N,j); % Solid phases 1 = C(s) elseif M == 5 CEA(j,2) = y(43)*SEM(43,j); % Solid phases 1 = C(s) CEA(j,3) = y(44)*SEM(44,j); % Solid phases 2 = S(s) elseif M == 6 CEA(j,2) = y(46)*SEM(46,j); % Solid phases 1 = C(s) CEA(j,3) = y(47)*SEM(47,j); % Solid phases 2 = S(s) end end end end Appendix J Matlab code for thermodynamic equilibrium calculation 222 A p p en d ices J.5 Standard chemical potential File name: mut.m Function: To compute the standard chemical potential of each species --------------------------------------------------------------------------------- function [smu,smustar] = mut(T,p,Dat1,Dat11) % Mut calculates the standard chemical potential mu* at (T,p) % smu, smustar: kJ/mol [N,NN] = size(Dat1); % NN is useless but recorded here. R = 8.31448; smustar = zeros(N,1); for i = 1:N Tcut(i) = Dat1(i,8); if T > 1177.00 Dat1(44,2) = 2; % Na becomes vapour at thes temperature end smu(i) = Dat1(i,3) + Dat1(i,4)*T*log(T) + Dat1(i,5)*T^2 + Dat1(i,6)/T + Dat1(i,7)*T; if T > Tcut(i) % Alternative correlations for DGfo(T) smu(i) = Dat11(i,3) + Dat11(i,4)*T*log(T) + Dat11(i,5)*T^2 + Dat11(i,6)/T + Dat11(i,7)*T; end if Dat1(i,2) == 2 % For condensed phase smustar(i) = smu(i); % mu* = DGfo(T), ignoring vapour term elseif Dat1(i,2) == 1 % For gas phase smustar(i) = smu(i) + R * T * log(p) / 1000; end end Appendix J Matlab code for thermodynamic equilibrium calculation 223 A p p en d ices J.6 Species enthalpy File name: enth.m Function: To compute the enthalpy of each species --------------------------------------------------------------------------------- function [h,H] = enth(Dath,Dath1,T,y) % ENTH computes the enthalpy of each species, unit in kJ/mol [N,M] = size(Dath); H = zeros(N,1); for i = 1:N if T <= Dath(i,8) h(i) = Dath(i,3)*T/1000 + Dath(i,4)*T^2/1000000 + Dath(i,5)/T + Dath(i,6); else h(i) = Dath1(i,3)*T/1000 + Dath1(i,4)*T^2/1000000 + Dath1(i,5)/T + Dath1(i,6); end H(i) = h(i).*y(i); end Appendix J Matlab code for thermodynamic equilibrium calculation 224 A p p en d ices J.7 Elements in the RAND matrix File name: abzuc.m Function: To compute the RAND matrix A and vector B --------------------------------------------------------------------------------- function [a1,b1,ra1,ra2] = abzuc(SI,SEM,EA,CEA,EA0,smutp,T,p,y,imm) % ABZUC calculates the RAND matrix elements a1(N3,N3) % In RAND algorithm, the Lagrange multipliers are solved from a1.x = b1 [N,M] = size(SEM); % (1) Count the number of gas, liquid and solid species ngas = 0; nliq = 0; nsol = 0; for i = 1:N if SI(i) == 1 ngas = ngas + 1; elseif SI(i) == 2 nliq = nliq + 1; elseif SI(i) == 3 nsol = nsol + 1; end end % Count the number of phases NP = 1; % Gas phase as an ideal solution if nliq > 0 NP = NP + 1; % Liquid phase as another ideal solution end NP = NP + nsol; % Each solid as a single-species phase if nliq > 0 NP = nsol + 2; else NP = nsol + 1; end NZ = 0; % Number of inert species N1 = N - NZ; % Number of reactive species N2 = M + 1; N3 = M + NP; R = 8.31448; if min(EA0) > 0.0001 yz = 0.005*min(EA0); else yz = 0.0000005; end a1 = zeros(N3,N3); Appendix J Matlab code for thermodynamic equilibrium calculation 225 A p p en d ices b1 = zeros(N3,1); % (2) Compute a1 matrix % Zone I - [j <= M, k <= M] for j = 1:M for k = j:M for i = 1:N1 a1(j,k) = a1(j,k)+SEM(i,j)*SEM(i,k)*y(i); end a1(k,j) = a1(j,k); end end % Zone II - [j <= M, k > M] for j = 1:M for k = N2:N3 a1(j,k) = CEA(j,(k-M)); end end % Zone III - [j > M, k <= M] for j = N2:N3 for k = 1:M a1(j,k) = CEA(k,(j-M)); end end % Zone IV - [j > M, k > M] for j = N2:N3 for k = N2:N3 % Note that for k > M, k = M + phase index l. % if j == N2 & k == N2 if j == k if j == N2 a1(j,k) = - yz; % Moles of inert species in gas phase. else a1(j,k) = - yz/100; end else a1(j,k) = 0; end end end ra1 = rank(a1); ra2 = cond(a1); % (3) Compute b1 vector % Zone I - [j <= M] for j = 1:M b1(j) = b1(j) + EA0(j) - EA(j); % Checked correct for i = 1:N1 b1(j) = b1(j) + SEM(i,j)*y(i)*smutp(i)*1000/(R*T); end end % EA0(j): the initial element abundance vector estimated from feed data. % EA(j): the element abundance of the current iteration. Appendix J Matlab code for thermodynamic equilibrium calculation 226 A p p en d ices % The incorporation of EA0(j)-EA(j) on the right side is believed to help prevent error accumulation. % Zone II - [j > M] for j = N2:N3 if j == N2 % Gas phase for i = 1:N b1(N2) = b1(j) + y(i)* (SI(i) == 1) * smutp(i)*1000/(R*T); % RT is timed by 1000 because the unit of smutp is kJ/mol end elseif j >= N2 + 1 if nliq > 0 % or M >= 7 for i = 1:N b1(N2+1) = b1(j) + y(i) * (SI(i) == 2) * smutp(i)*1000/(R*T); % RT is timed by 1000 because the unit of smutp is kJ/mol end else if M == 3 b1(N2+1) = y(N)*smutp(N)*1000/(R*T); % SSP-1: C(s) elseif M == 4 b1(N2+1) = y(N)*smutp(N)*1000/(R*T); % SSP-1: C(s) elseif M == 5 b1(N2+1) = y(43)*smutp(43)*1000/(R*T); % SSP-1: C(s) b1(N2+2) = y(44)*smutp(44)*1000/(R*T); % SSP-1: S(s) end % Add other single-species phases here: % b1(N2+2) = ... end end end if imm == 1 if ra1 ~= M + NP disp(' ') disp([' Rank of RAND coefficient matrix = ' num2str(ra1) ]) disp([' Condition number of RAND matrix = ' num2str(ra2) ]) disp(' ') elseif ra2 > 50000000 disp(' ') disp([' Condition number of RAND matrix = ' num2str(ra2) ]) disp(' ') end end Appendix J Matlab code for thermodynamic equilibrium calculation 227 A p p en d ices J.8 Convergence forcer File name: forcer.m Function: To speed up convergence by ensuring non-negativity of each species ------------------------------------------------------------------------------- function [ynew] = forcer(dy,y) % FORCER computes new mole numbers and guarantee their non-negativity. % Do not modify anything in this function. n = length(dy); par = 0.5; ynew = zeros(n,1); for i = 1:n if par < -dy(i)/y(i) par = -dy(i)/y(i); end end par = 1/par; if par > 0 & par <= 1 if par < 0.1 par = par * 0.999; else par = par * 0.99; end else par = 1.0; end for i = 1:n ynew(i) = y(i) + dy(i) * par; if ynew(i) <= 1e-200 % minimum value control ynew(i) = 1e-200; end end Appendix J Matlab code for thermodynamic equilibrium calculation 228 A p p en d ices J.9 Energy balance File name: heatcoal.m Function: Energy balance modulus ------------------------------------------------------------------------------- function [dq,totdh,totdgh,toth,totph,totgh,totsh] = heatcoal(T,alfa,Dath,Dat2,Dat3,NF,H,y,Uwat,Ca,dissip,Hfeed,hff,tstm) % HEATCOAL does energy balance for coal and biomass gasification. % All results are per 1 kg of biomass (dry basis) % Version 1.0 Masakazu Sakaguchi modified Xiantian Li's code (Jan. 3, 2010) % Initialization [N,M] = size(Dath); toth = 0; totdh = 0; totdgh = 0; totdlh = 0; totdsh = 0; totph = 0; totgh = 0; totsh = 0; %totdh25 = 0; htrans = 0; dq = 0; calcin = 0; sure = 0; sure0 = 0; dhsure = 0; tfactor = 0; afactor = 0; uncal = 0; sulfate = 0; spentlime= 0; ttt = 0; hcal = 0; huncal = 0; huncal = 0; hsulfate= 0; hsptlime= 0; calcium = 0; % End of initialization % (1) Enthalpy of feedstock: Hfeed hfeed = Hfeed; % kJ (sensible heat) % (2) Total product heat of formation @298K and enthalpy at T for i = 1:N totdh = totdh + Dath(i,7) * y(i); % Total heat of formation, kJ toth = toth + H(i); % System total enthalpy, kJ if Dath(i,2) == 1 Appendix J Matlab code for thermodynamic equilibrium calculation 229 A p p en d ices totdgh = totdgh + H(i); elseif Dath(i,2) == 2 totdlh = totdlh + H(i); elseif Dath(i,2) == 3 totdsh = totdsh + H(i); end end % Calculate fractional calcination and sulfur retention if Ca >= 0.1 % If sorbent is added for sulfur removal [sure,calcin] = sulfre(T,alfa,Ca); % Sulfur retention products (basis: 1 kg of fuel) sulfur = (Dat3(9,NF)/100)*1000/32.066; % Moles of sulfur in 1 kg fuel calcium = sulfur*Ca; % Moles of Ca added hcal = calcium*calcin*(-178.989); % Heat effect of calcination uncal = calcium*(1-calcin); % Moles of uncalcined CaCO3 sulfate = sulfur*sure; % Moles of CaSO4 formed hsulf = sulfate*502.179; % Heat effect of sulfation spentlime= (calcium - uncal)-sulfate; % Moles of spent lime dhsure = hcal + hsulf; % Net heat effect of sulf-re % Sensible heat (enthalpy) of sulfur retention products huncal = uncal* (97.935*T/1000 + 14.198*T^2/1000000 + 1855.4379/T - 36.8346); % CaCO3 hsulfate= sulfate* (32.863*T/1000 + 61.278*T^2/1000000 - 6316.038/T + 4.5425); % CaSO4 hsptlime= spentlime* (48.997*T/1000 + 2.5140*T^2/1000000 + 573.2851/T - 16.8339); % CaO end % Old ash in fuel oldash = Dat3(3,NF)/100; % kg/kg_fuel (Note: not mol/kg_fuel) holdash = oldash*(1.15e-4*T^2 + 0.82709*T - 239.38); % kJ/kg_fuel % New ash from sulfur retention newash = uncal + sulfate + spentlime; % mol/kg_fuel hnewash = huncal + hsulfate + hsptlime; % kJ/kg_fuel htotash = holdash + hnewash; % kJ/kg_fuel % Modification of gas and solid enthalpy totgh = toth; for i=1:N if Dath(i,2) ~= 1 totgh = totgh - H(i); % Total gas enthalpy, kJ/kg_fuel if Dath(i,2) == 3 totsh = totsh + H(i); % Total solid enthalpy, kJ/kg_fuel end end end totsh = totsh + htotash; totph = totgh + totsh; % Total product enthalpy, kJ/kg_fuel % Reduction of SO2 moles due to sulfur retention is already considered in elemental abundance % (3) Heat of formation of the feed: From Dath hf1 = hff; % Fuel, kJ/kg_fuel hf2 = Uwat*Dath(17,7); % DHfo(298) for H2O (vapour), kJ/kg_fuel hf3 = -1207.6*calcium; % Heat of formation of limestone hffeed = hf1 + hf2 + hf3; % kJ/kg_fuel Appendix J Matlab code for thermodynamic equilibrium calculation 230 A p p en d ices % (4) Reactor surface heat transfer in this time interval (preset as 1 hr) htrans = dissip; %dissipation from reactor surface % (5) Heat required to maintain the current temperature (kJ/kg_fuel) dq = (totdh + toth + htrans) - (hffeed + hfeed + dhsure); % HHV already considered in hff, kJ/kg_fuel (as received) Appendix J Matlab code for thermodynamic equilibrium calculation 231 A p p en d ices J.10 Reference Li, X. (2002) Biomass gasification in a circulating fluidized bed. PhD thesis, The University of British Columbia, Vancouver.